Asthma

Resident Survival Guide

Asthma Microchapters
Home
Patient Information
Overview
Historical Perspective
Classification
Pathophysiology
Causes
Differentiating Asthma from other Diseases
Epidemiology and Demographics
Risk Factors
Screening
Natural History, Complications and Prognosis
Diagnosis
History and Symptoms
Physical Examination
Laboratory Findings
Electrocardiogram
Chest X Ray
CT
MRI
Other Imaging Findings
Other Diagnostic Studies Pulmonary Function Test Bronchial Challenge Test Exhaled nitric oxide
Treatment
Emergency Management
Medical Therapy
Alternative and Complementary Medicine
Bronchial Thermoplasty
Primary Prevention
Secondary Prevention
Cost-Effectiveness of Therapy
Future or Investigational Therapies
Case Studies
Case #1
Asthma On the Web
Most recent articles
Most cited articles
Review articles
CME Programs
Powerpoint slides
Images
American Roentgen Ray Society Images of Asthma All Images X-rays Echo & Ultrasound CT Images MRI
Ongoing Trials at Clinical Trials.gov
US National Guidelines Clearinghouse
NICE Guidance
FDA on Asthma
CDC on Asthma
Asthma in the news
Blogs on Asthma
Directions to Hospitals Treating Asthma
Risk calculators and risk factors for Asthma

For patient information, click here.

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Omar Elshafei, MD[2]; Philip Marcus, M.D., M.P.H. [3]; Associate Editor(s)-in-Chief: Varun Kumar, M.B.B.S. [4], Lakshmi Gopalakrishnan, M.B.B.S. [5]

Synonyms and keywords: Bronchial asthma; allergic asthma; eosinophilic asthma; type 2 asthma; cough-variant asthma; status asthmaticus

Overview

Asthma is a heterogeneous chronic disease usually characterized by chronic airway inflammation. It is defined by a history of respiratory symptoms such as wheeze, shortness of breath, chest tightness, and cough that vary over time and in intensity, together with variable expiratory airflow limitation that may later become persistent. Airway hyperresponsiveness and type 2 airway inflammation, driven by interleukin 4, interleukin 5, and interleukin 13 released from T helper 2 cells and group 2 innate lymphoid cells, are central features in many, but not all, patients. The World Health Organization estimated that asthma affected 363 million people and caused 442,000 deaths in 2023, and asthma is the most common chronic disease of childhood. In the United States, 24,963,874 people (7.7%) had current asthma in 2021. The diagnosis is based on a characteristic pattern of symptoms confirmed by objective evidence of variable expiratory airflow limitation, most often with spirometry and bronchodilator responsiveness testing, peak expiratory flow variability, or bronchial provocation testing; fractional exhaled nitric oxide (FeNO) and blood eosinophil counts support the diagnosis of type 2 asthma. When adults with physician-diagnosed asthma are retested, asthma is ruled out in about one-third, which underlines the importance of objective confirmation. Current guidelines recommend that all adolescents and adults with asthma receive inhaled corticosteroid (ICS)-containing treatment and advise against treatment with a short-acting beta2-agonist (SABA) alone. The preferred approach in adults and adolescents is low-dose ICS-formoterol used as an anti-inflammatory reliever (AIR), either alone in mild asthma or as maintenance-and-reliever therapy (MART) in moderate to severe asthma. Patients with severe asthma may benefit from an add-on long-acting muscarinic antagonist, azithromycin, or biologic therapy targeting immunoglobulin E, interleukin 5 or its receptor, the interleukin 4 receptor alpha subunit, or thymic stromal lymphopoietin. Acute exacerbations are treated with repeated inhaled bronchodilators, ipratropium bromide in moderate to severe attacks, early systemic corticosteroids, and controlled oxygen therapy, with intravenous magnesium sulfate reserved for severe exacerbations that respond poorly to initial treatment.

Historical Perspective

• The word asthma is derived from the Greek word for panting.
• In 1993, the Global Initiative for Asthma (GINA) was established; its first report was published in 1995, and the report has been updated annually since 2002.
• In 2007, the National Asthma Education and Prevention Program Expert Panel Report 3 (EPR-3) introduced the assessment of asthma severity and control across the domains of impairment and risk, linked to a stepwise approach to therapy.
• Between 2008 and 2010, unbiased cluster analyses identified distinct clinical asthma phenotypes, and airway gene expression studies separated asthma into T helper 2 (Th2)-high and Th2-low subphenotypes.
• In 2009, an official American Thoracic Society/European Respiratory Society statement standardized the concept of asthma control as two domains: current clinical control and future risk.
• In 2014, the ERS/ATS guidelines provided an international definition of severe asthma.
• In 2018, the SYGMA 1 and SYGMA 2 trials showed that as-needed budesonide-formoterol was effective in mild asthma, and since 2019 GINA has recommended low-dose ICS-formoterol as an anti-inflammatory reliever in place of SABA-only treatment.
• In 2020, the NAEPP focused updates addressed six topics: FeNO testing, indoor allergen mitigation, intermittent ICS and single maintenance and reliever therapy (SMART), long-acting muscarinic antagonists, allergen immunotherapy, and bronchial thermoplasty.
• In 2024, the British Thoracic Society, the National Institute for Health and Care Excellence (NICE), and the Scottish Intercollegiate Guidelines Network published a joint guideline (NG245) that replaced NICE NG80 and parts of SIGN 158.
• The 2026 GINA update added twice-yearly depemokimab, the first biosimilar anti-IgE antibody (omalizumab-igec), as-needed ICS-SABA across all Track 2 steps, and budesonide-glycopyrronium-formoterol triple therapy, and substantially revised acute asthma management.

Classification

Asthma may be classified by level of control, by severity, by clinical and inflammatory phenotype, and by trigger or setting.

Classification by Control

• Asthma control has two domains: symptom control over the previous 4 weeks (well controlled, partly controlled, or uncontrolled) and future risk of adverse outcomes, including exacerbations, persistent airflow limitation, and medication side effects. The criteria are shown under Assessment of Control and Future Risk.

Classification by Severity

GINA assesses severity retrospectively, from the level of treatment needed to control symptoms and exacerbations:

• Mild asthma: well controlled with as-needed low-dose ICS-formoterol or low-dose maintenance ICS.
• Difficult-to-treat asthma: uncontrolled despite medium- or high-dose ICS-long-acting beta2-agonist (LABA) or maintenance oral corticosteroids (OCS), or requiring high-dose treatment to maintain good control. The term does not mean a "difficult patient."
• Severe asthma: a subset of difficult-to-treat asthma that is uncontrolled despite good adherence to optimized high-dose ICS-LABA and management of contributory factors, or that needs high-dose ICS-LABA to maintain control.
• Uncontrolled asthma is defined as poor symptom control and/or frequent exacerbations (≥2 per year requiring OCS) or serious exacerbations (≥1 per year requiring hospitalization).
• The ERS/ATS guidelines define severe asthma as asthma that requires high-dose ICS plus a second controller and/or systemic corticosteroids to prevent it from becoming uncontrolled, or that remains uncontrolled despite this therapy, after the diagnosis has been confirmed and comorbidities have been addressed.
• The NAEPP EPR-3 classifies severity in patients 12 years and older who are not yet taking long-term control therapy as shown below.

Component (age ≥12 years)	Intermittent	Mild persistent	Moderate persistent	Severe persistent
Symptoms	≤2 days/week	>2 days/week but not daily	Daily	Throughout the day
Nighttime awakenings	≤2 times/month	3-4 times/month	>1 time/week but not nightly	Often 7 times/week
SABA use for symptom control	≤2 days/week	>2 days/week but not daily, and not more than 1 time on any day	Daily	Several times per day
Interference with normal activity	None	Minor limitation	Some limitation	Extremely limited
Lung function	Normal FEV1 between exacerbations; FEV1 >80% predicted; FEV1/FVC normal	FEV1 >80% predicted; FEV1/FVC normal	FEV1 >60% but <80% predicted; FEV1/FVC reduced 5%	FEV1 <60% predicted; FEV1/FVC reduced >5%
Exacerbations requiring oral systemic corticosteroids	0-1/year	≥2/year

Classification by Clinical Phenotype

Phenotypes are recognizable clusters of demographic, clinical, and pathophysiologic characteristics. Apart from severe asthma, they do not correlate strongly with specific pathologic features or with treatment response.

Phenotype	Characteristic features	Clinical implications
Allergic asthma	Often begins in childhood; personal or family history of allergic disease such as eczema, allergic rhinitis, or food or drug allergy; sputum often shows eosinophilic airway inflammation	Usually responds well to ICS
Non-allergic asthma	Not associated with allergy; sputum may be neutrophilic, eosinophilic, or paucigranulocytic	Often less short-term response to ICS
Cough-variant or cough-predominant asthma	Cough may be the only symptom	Requires objective evidence of variable airflow limitation or airway hyperresponsiveness
Adult-onset (late-onset) asthma	More common in women; often non-allergic	Often requires higher ICS doses or is relatively refractory; exclude occupational asthma
Asthma with persistent airflow limitation	Long-standing asthma with incompletely reversible airflow limitation, attributed to airway wall remodeling	Risk factors include no ICS treatment despite severe exacerbations, exposure to tobacco smoke or noxious agents, low FEV1 at diagnosis, and high blood eosinophil counts
Asthma with obesity	Prominent respiratory symptoms with little eosinophilic airway inflammation	Weight management is part of treatment

Classification by Inflammatory Endotype

• Type 2-high asthma is driven by interleukin 4, interleukin 5, and interleukin 13 produced by Th2 cells or group 2 innate lymphoid cells, leading to eosinophilia, mucus production, bronchial hyperresponsiveness, immunoglobulin E (IgE) production, and exacerbations. Only about half of patients have type 2-high asthma.
• Type 2-low asthma is associated with obesity, neutrophilic inflammation, and corticosteroid unresponsiveness.
• In airway epithelial gene expression studies of 42 patients with mild to moderate asthma and 28 healthy controls, patients separated into two evenly sized Th2-high and Th2-low subgroups; the Th2-low group was indistinguishable from controls, and the improvement in lung function with ICS was restricted to the Th2-high group.

Cluster-Derived Phenotypes

• Cluster analysis identified early-onset atopic asthma and obese non-eosinophilic asthma in both primary care and refractory asthma populations, and two discordant phenotypes specific to refractory asthma: early-onset symptom-predominant asthma and late-onset inflammation-predominant asthma. In inflammation-predominant asthma, sputum eosinophil-guided management reduced exacerbations (3.53 versus 0.38 per patient per year), and in symptom-predominant asthma it allowed a reduction in ICS dose of 1,829 mcg beclomethasone-equivalent per day.
• The Severe Asthma Research Program identified 5 clusters among 726 subjects: early-onset atopic asthma with normal lung function (cluster 1, n=110); early-onset atopic asthma with preserved lung function but greater medication use and health care utilization (cluster 2, n=321); late-onset, non-atopic asthma in older obese women with frequent OCS use (cluster 3, n=59); and severe airflow obstruction with bronchodilator responsiveness (clusters 4 and 5, n=120 and n=116).

Childhood Wheezing Phenotypes

In a birth cohort of 826 children followed to 6 years of age, 51.5% never wheezed, 19.9% had transient early wheezing, 15.0% had late-onset wheezing, and 13.7% had persistent wheezing. Transient early wheezing was associated with diminished airway function and maternal smoking but not with atopy, whereas persistent wheezing was associated with maternal asthma and elevated serum IgE.

Classification by Trigger or Setting

• Work-related asthma includes occupational asthma (sensitizer-induced or irritant-induced) and work-exacerbated asthma.
• Exercise-induced bronchoconstriction is airway narrowing triggered by exercise.
• Non-steroidal anti-inflammatory drug (NSAID)-exacerbated respiratory disease (N-ERD) is a chronic eosinophilic inflammatory disorder of the airways in patients with asthma and/or chronic rhinosinusitis with nasal polyps, in whom symptoms are exacerbated by NSAIDs, including aspirin. It affects about 1 in 10 patients with asthma and rhinosinusitis.

Differentiating Asthma from other Diseases

• Many conditions cause wheeze, cough, or breathlessness, and the conditions to consider differ by age.
• Misdiagnosis is common. Among 613 adults with physician-diagnosed asthma who underwent re-evaluation, asthma was ruled out in 203 (33.1%; 95% CI, 29.4%-36.8%), and 12 (2.0%) had serious cardiorespiratory conditions that had been misdiagnosed as asthma. Patients in whom asthma was ruled out were less likely to have undergone objective testing at the time of the initial diagnosis (43.8% versus 55.6%).
• In primary care, the diagnosis of asthma cannot be confirmed in 25%-35% of patients who carry the diagnosis.

Differential Diagnosis by Age

Age group	Conditions to consider
6-11 years	Chronic upper airway cough syndrome; inhaled foreign body; bronchiectasis; protracted bacterial bronchitis; inborn errors of immunity; primary ciliary dyskinesia; congenital heart disease; bronchopulmonary dysplasia; cystic fibrosis
12-39 years	Chronic upper airway cough syndrome; cough hypersensitivity syndrome; gastroesophageal reflux disease; inducible laryngeal obstruction; hyperventilation and dysfunctional breathing; bronchiectasis; cystic fibrosis; heart disease; alpha1-antitrypsin deficiency; inhaled foreign body
40 years and older	Cough hypersensitivity syndrome; gastroesophageal reflux disease; inducible laryngeal obstruction; dysfunctional breathing; chronic obstructive pulmonary disease (COPD); bronchiectasis; cardiac failure; medication-related cough from angiotensin-converting enzyme (ACE) inhibitors; parenchymal lung disease; pulmonary embolism; central airway obstruction
All ages	Tuberculosis; pertussis

Adapted from the GINA 2026 report.

Distinguishing Asthma from Common Mimics

Condition	Features that help distinguish it from asthma	Key investigations
COPD	Usually age ≥40 years; history of smoking or other noxious exposure; chronic productive cough; airflow limitation that persists after bronchodilator. Asthma and COPD may coexist.	Post-bronchodilator spirometry
Inducible laryngeal obstruction (including vocal cord dysfunction)	Inappropriate, transient, reversible narrowing of the larynx in response to external triggers; exercise-induced breathlessness with noisy inspiration	Laryngoscopy during symptoms or during provocation
Cardiac failure	Older age; breathlessness with crackles on auscultation (crackles are not a feature of asthma)	Chest X-ray, electrocardiogram, echocardiography
Bronchiectasis, cystic fibrosis, primary ciliary dyskinesia	Chronic productive cough and recurrent respiratory infections	Computed tomography (CT) of the chest; sweat test for cystic fibrosis
Inhaled foreign body and central airway obstruction	Localized or unilateral wheeze; inspiratory noise; poor response to bronchodilators	Chest imaging; flow-volume loop; bronchoscopy
Dysfunctional breathing and hyperventilation	Dizziness, light-headedness, and peripheral paresthesia; may coexist with asthma	Spirometry, bronchodilator responsiveness, and bronchial challenge testing to exclude asthma
Pulmonary embolism	Sudden-onset breathlessness, chest pain	CT pulmonary angiography
Allergic bronchopulmonary aspergillosis (ABPA; a complication of asthma)	Poorly controlled asthma with mucus plugging and bronchiectasis	Fungal sensitization plus total IgE ≥500 IU/mL plus two of: fungus-specific immunoglobulin G, blood eosinophilia, or suggestive imaging
Eosinophilic granulomatosis with polyangiitis (EGPA)	Asthma or other obstructive airway disease with marked blood eosinophilia, nasal polyps, and features of vasculitis such as mononeuritis multiplex	2022 American College of Rheumatology/EULAR classification criteria: maximum eosinophil count ≥1 x 109/L (+5), obstructive airway disease (+3), nasal polyps (+3), extravascular eosinophilic-predominant inflammation (+2), mononeuritis multiplex or motor neuropathy (+1), cytoplasmic ANCA or anti-proteinase 3 antibodies (-3), and hematuria (-1); a score of ≥6 classifies EGPA with a sensitivity of 85% and a specificity of 99%. These are classification criteria validated for research use, applied only after small- or medium-vessel vasculitis has been diagnosed and mimics have been excluded
ACE inhibitor-related cough	Dry cough in a patient taking an ACE inhibitor	Improvement after the drug is stopped

Epidemiology and Demographics

Prevalence

• The World Health Organization estimated that asthma affected 363 million people worldwide in 2023, and it is the most common chronic disease among children.
• Estimates vary with the data sources and modeling methods used. The Global Burden of Disease (GBD) 2021 study estimated 260 million (95% uncertainty interval, 227-298 million) prevalent cases in 2021, compared with 287 million in 1990. Between 1990 and 2021, the age-standardized prevalence decreased by 40.0%, from 5568.3 to 3340.1 per 100,000 population, and the number of cases is forecast to reach 275 million (224-330 million) by 2050.
• The prevalence of asthma ranges from 1% to 29% in different countries.
• In the Global Asthma Network Phase I study of 119,795 school-aged children (6-7 and 13-14 years) from 27 centres in 14 countries, about one in ten children had wheeze in the previous year, and almost half of them had severe symptoms. Current wheeze decreased in low-income countries, increased in lower-middle-income countries, and remained stable in upper-middle-income and high-income countries.
• In a Dutch population-based study, 3.6% (95% CI, 3.0%-4.1%) of adults with asthma had severe refractory asthma, equivalent to 10.4 per 10,000 inhabitants. In the same population, 24% of adults with asthma were treated at GINA Steps 4-5 and 17% had difficult-to-treat asthma.
• Severe asthma is estimated to affect 5% to 10% of patients with asthma, although estimates vary with the definition used, and it accounts for close to one-half of asthma-related medical costs.

Mortality and Disease Burden

• Asthma caused an estimated 442,000 deaths worldwide in 2023, most of them in low- and lower-middle-income countries.
• Asthma morbidity and mortality have improved over the past 15 years, but undertreatment remains common.
• In GBD 2021, the highest age-standardized disability-adjusted life-year (DALY) rate was in south Asia (465.0 per 100,000), and modifiable risk factors accounted for 29.9% of asthma DALYs.
• In the United States in 2020, there were 986,453 emergency department visits (29.8 per 10,000) and 94,560 hospital stays (2.9 per 10,000) for asthma, and in 2021, 39.4% of people with current asthma reported one or more asthma attacks in the previous year.

Demographics in the United States

Population	Current asthma, 2021	Asthma deaths, 2021 (rate per million)
Total	24,963,874 (7.7%)	3,517 (10.6)
Children (<18 years)	4,675,475 (6.5%)	145 (2.0)
Adults (≥18 years)	20,288,399 (8.0%)	3,372 (13.1)
Adults ≥65 years	Not listed	1,513 (27.1)
Males	6.5% (boys 7.3%; men 6.2%)	1,430 (8.7)
Females	8.9% (girls 5.6%; women 9.7%)	2,087 (12.5)
White, non-Hispanic	7.6%*	1,929 (9.8)
Black, non-Hispanic	10.9%*	1,020 (24.4)
Hispanic	6.4%*	366 (5.8)
American Indian or Alaska Native, non-Hispanic	12.3%*	Not listed
Asian, non-Hispanic	4.1%*	Not listed
Multiple races, non-Hispanic	10.3%*	Not listed
Below 100% of the poverty threshold	10.4%	Not listed

*Combined data for 2019-2021. Source: Centers for Disease Control and Prevention.

• Age and sex: Asthma is more common in boys than in girls, but more common in women than in men.
• Race and ethnicity: Prevalence is highest among American Indian or Alaska Native and Black non-Hispanic people, and the asthma death rate among Black non-Hispanic people is more than twice that among White non-Hispanic people.
• Socioeconomic status: Prevalence is higher among people living below the poverty threshold.
• Occupation: About 16% of adult asthma is attributable to occupational exposures (population attributable fraction).

Pathophysiology

Airway Inflammation, Hyperresponsiveness, and Airflow Limitation

• Asthma is characterized by chronic airway inflammation and variable expiratory airflow limitation, which may become persistent over time. Airway hyperresponsiveness and airway inflammation are common, but they are neither necessary nor sufficient for the diagnosis.
• Airflow limitation results from bronchial smooth muscle contraction, mucus hypersecretion, and structural changes in the airway wall (remodeling).

Type 2 Inflammation

• Epithelial-derived cytokines (alarmins), including thymic stromal lymphopoietin (TSLP) and interleukin 33, are released when the airway epithelium is exposed to allergens, viruses, and pollutants, and they activate dendritic cells, Th2 cells, and group 2 innate lymphoid cells.
• These cells release interleukin 4, interleukin 5, and interleukin 13:
  • Interleukin 4 drives IgE class switching in B cells. IgE bound to mast cells triggers release of histamine, leukotrienes, and prostaglandins on re-exposure to allergen, causing bronchoconstriction.
  • Interleukin 5 promotes the maturation, recruitment, and survival of eosinophils.
  • Interleukin 13 promotes goblet cell metaplasia, mucus hypersecretion, and bronchial hyperresponsiveness, and increases epithelial production of nitric oxide, the basis of FeNO measurement.
• Each step of this cascade is targeted by a biologic: IgE (omalizumab), interleukin 5 (mepolizumab, reslizumab, depemokimab), the interleukin 5 receptor (benralizumab), the interleukin 4 receptor alpha subunit that mediates both interleukin 4 and interleukin 13 signaling (dupilumab), and TSLP (tezepelumab).

Type 2-Low Inflammation

• About half of patients do not have type 2-high inflammation. Type 2-low asthma is associated with obesity, neutrophilic inflammation, and corticosteroid unresponsiveness.

Airway Remodeling and Mucus Plugging

• In 48 subjects with asthma, repeated bronchoconstriction induced by either allergen or methacholine produced similar degrees of airway remodeling, including thickening of the subepithelial collagen band and increased goblet-cell mucus staining, although only allergen increased eosinophilic inflammation. This suggests that mechanical bronchoconstriction itself can drive remodeling.
• On multidetector CT, mucus plugs were present in at least 1 of 20 bronchopulmonary segments in 58% of patients with asthma compared with 4.5% of healthy controls, and they persisted for years in the same segments. A high mucus score was found in 67% of patients with FEV1 <60% predicted, 19% of those with FEV1 60%-80% predicted, and 6% of those with FEV1 >80% predicted, and was associated with sputum eosinophilia and eosinophil peroxidase.

Genetics

• A genome-wide association study of 10,365 cases and 16,110 controls identified asthma susceptibility loci at IL1RL1/IL18R1, HLA-DQ, IL33, SMAD3, and IL2RB. The ORMDL3/GSDMB locus on chromosome 17q21 was associated specifically with childhood-onset asthma, and loci that regulate total serum IgE levels were not associated with asthma.

Environmental and Microbial Influences

• Viral infections: In a high-risk birth cohort of 259 children, wheezing illnesses during the first 3 years of life caused by respiratory syncytial virus (odds ratio [OR] 2.6), rhinovirus (OR 9.8), or both (OR 10) predicted asthma at 6 years of age. Nearly 90% (26 of 30) of children who wheezed with rhinovirus in the third year of life had asthma at 6 years.
• Farm and microbial exposure: Children exposed to a wider range of environmental microorganisms had a lower risk of asthma (OR 0.62 [95% CI, 0.44-0.89] in the PARSIFAL study and 0.86 [95% CI, 0.75-0.99] in the GABRIELA study). The prevalence of asthma was 4 times lower and that of allergic sensitization 6 times lower in Amish than in Hutterite farm children, and endotoxin levels in Amish house dust were 6.8 times higher. Amish house dust prevented airway hyperresponsiveness and eosinophilia in a mouse model, an effect that was abrogated in mice deficient in the innate immune signaling molecules MyD88 and Trif.

Causes

• Asthma results from interactions between genetic susceptibility and environmental exposures, and it is often difficult to identify a single direct cause.
• Common triggers of symptoms and exacerbations include:
  • Viral respiratory infections, including the common cold
  • Allergens such as house dust mites, pollen, moulds, and animal fur or feathers
  • Tobacco smoke, indoor and outdoor air pollution, fumes, strong soaps, and perfume
  • Exercise, laughter, and changes in weather
  • NSAIDs, including aspirin, in patients with N-ERD
  • Occupational sensitizers and irritants

Risk Factors

Category	Risk factor	Supporting evidence
Host factors	Family history of asthma; personal history of other allergic conditions such as eczema and allergic rhinitis	Susceptibility loci at IL33, IL1RL1, and ORMDL3/GSDMB
Sex and age	Male sex in childhood; female sex in adulthood	Current asthma in boys 7.3% versus girls 5.6%, and in women 9.7% versus men 6.2%
Early life	Low birth weight, prematurity, exposure to tobacco smoke and air pollution, and viral respiratory infections	Rhinovirus wheezing illness in the first 3 years of life (OR 9.8)
Environmental exposures	Indoor and outdoor air pollution, house dust mites, moulds, and urbanization	Nitrogen dioxide and smoking are among the modifiable risk factors in GBD 2021
Occupational exposures	Chemicals, fumes, and dust in the workplace	Population attributable fraction of 16%; occupational asthmagens accounted for an age-standardized DALY rate of 20.8 per 100,000
Overweight and obesity	Increased risk of asthma	High body mass index accounted for an age-standardized DALY rate of 39.4 per 100,000
Protective factor	Farm environment with diverse microbial exposure	Lower asthma risk with greater microbial diversity

Screening

• Major guidelines focus on targeted case-finding in people with respiratory symptoms or related conditions rather than on population screening of asymptomatic people.
• Patients with allergic rhinitis or atopic dermatitis should be asked about respiratory symptoms. Undiagnosed asthma is associated with worse quality of life and more unscheduled health care visits.
• In a randomized trial of community case-finding, 38,353 people were interviewed, 595 were found to have undiagnosed asthma or COPD, and 508 were randomized. Pulmonologist-directed treatment reduced respiratory health care utilization compared with usual care (0.53 versus 1.12 events per person-year; incidence rate ratio [IRR] 0.48; 95% CI, 0.36-0.63).
• Targeted screening in patients with asthma:
  • Occupational asthma: Adults with new-onset asthma, poorly controlled asthma, or reappearance of childhood asthma should be asked whether symptoms improve on days away from work or on holidays.
  • ABPA: Screening for Aspergillus fumigatus sensitization (fungus-specific IgE) is recommended for all adults with newly diagnosed asthma seen in tertiary care, and only for children with difficult-to-treat asthma.
• Predicting asthma in young children with wheeze: The Asthma Predictive Index uses frequent wheezing during the first 3 years of life plus 1 major criterion (parental asthma or physician-diagnosed eczema in the child) or 2 of 3 minor criteria (blood eosinophilia ≥4%, wheezing without colds, or physician-diagnosed allergic rhinitis). A positive stringent index increased the likelihood of active asthma at 6-13 years by 4.3-9.8 times, and more than 95% of children with a negative stringent index never had active asthma. FeNO should not be used to predict future asthma in children 0-4 years of age with recurrent wheezing.

Natural History, Complications and Prognosis

Natural History

• Childhood to adulthood: In the Dunedin birth cohort of 613 participants followed to 26 years of age, 51.4% reported wheezing at more than one assessment; 14.5% had persistent wheezing, 27.4% had remission, and 12.4% relapsed after remission. Sensitization to house dust mites (OR 2.41 for persistence; 2.18 for relapse), airway hyperresponsiveness (OR 3.00 for persistence; 3.03 for relapse), female sex (OR 1.71 for persistence), and smoking at 21 years of age (OR 1.84 for persistence) predicted an unfavorable course.
• Lung function trajectories: Among 684 children with persistent asthma followed into adulthood, 25% had normal lung function growth and 75% had abnormal patterns (reduced growth with early decline, 26%; reduced growth only, 23%; normal growth with early decline, 26%). Seventy-three participants (11%) met spirometric criteria for COPD at a mean age of 26.0 years.
• Adult-onset asthma: Of 170 patients with adult-onset asthma followed for 5 years, 27 (15.9%) achieved clinical remission. Moderate to severe bronchial hyperresponsiveness and nasal polyps independently predicted persistence, and remission occurred in less than 1% of patients who had both.
• Remission: Clinical remission is defined as at least 12 months with absence of significant symptoms on a validated instrument, optimization and stabilization of lung function, patient and provider agreement, and no use of systemic corticosteroids. Complete remission additionally requires objective resolution of airway inflammation and, if appropriate, a negative test of bronchial hyperresponsiveness. The reported prevalence of remission in adults ranges from 2% to 52%; predictors include milder asthma, better lung function and control, younger age, early onset, shorter duration, milder bronchial hyperresponsiveness, fewer comorbidities, and not smoking.

Complications

• Life-threatening exacerbations, respiratory failure, and death
• Persistent airflow limitation
• Allergic bronchopulmonary aspergillosis
• Medication adverse effects:
  • Oral corticosteroids: In patients with asthma, ≥4 OCS prescriptions per year were associated with new adverse effects (OR 1.29; 1-3 prescriptions, OR 1.04), and each additional year with ≥4 prescriptions increased the odds (OR 1.20). Associated adverse effects included osteoporosis, hypertension, obesity, type 2 diabetes mellitus, gastrointestinal ulcers or bleeding, fractures, and cataracts (odds ratios 1.21-1.44). Even short courses carry risk: among 1,548,945 commercially insured adults 18-64 years of age in the United States (not limited to asthma), 21.1% received at least one short-term course of OCS over 3 years, and within 30 days the incidence of sepsis (IRR 5.30), venous thromboembolism (IRR 3.33), and fracture (IRR 1.87) increased, including at doses <20 mg/day.
  • Inhaled corticosteroids in children: Budesonide taken during childhood was associated with a 1.2 cm (95% CI, -1.9 to -0.5) lower adult height; the deficit was not progressive or cumulative.
• Adverse pregnancy outcomes, including low birth weight after severe exacerbations (see Special Populations)

Prognosis

• Risk factors for asthma-related death include a history of near-fatal asthma, a very severe exacerbation in the previous year, current or recent OCS use, and SABA overuse (more than 1 canister per month). Dispensing of ≥12 SABA canisters per year (and possibly fewer) and use of home-nebulized SABA are associated with a higher risk of death.
• In the SABINA cohort of 365,324 patients 12-45 years of age, 30% used ≥3 SABA canisters per year. Compared with use of fewer than 3 canisters, mortality was increased with 3-5 canisters (hazard ratio [HR] 1.26; 95% CI, 1.14-1.39), 6-10 canisters (HR 1.67; 1.49-1.87), and ≥11 canisters (HR 2.35; 2.02-2.72) per year.
• Regular ICS use is protective. In a cohort of 30,569 patients, the rate of death from asthma decreased by 21% for each additional ICS canister used in the previous year (rate ratio 0.79; 95% CI, 0.65-0.97).
• In the United States, the asthma death rate in 2021 was 10.6 per million overall and 27.1 per million among adults ≥65 years of age.

Diagnosis

History and Symptoms | Physical Examination | Laboratory Findings | Electrocardiogram | Chest X Ray | CT | MRI | Other Imaging Findings | Pulmonary Function Test | Bronchial Challenge Test | Exhaled nitric oxide

Diagnostic Approach

• The diagnosis of asthma is based on a history of characteristic symptom patterns together with objective evidence of variable expiratory airflow limitation. Testing should be performed before controller treatment is started whenever possible, because the diagnosis is more difficult to confirm afterwards.
• Asthma should not be diagnosed without both a suggestive history and at least one supporting objective test; until it is confirmed, the diagnosis should be recorded as suspected asthma.
• The ERS guideline for adults recommends spirometry with bronchodilator responsiveness testing first; if airflow obstruction is not demonstrated, FeNO is measured next, followed by PEF variability, and then bronchial challenge testing in secondary care.
• In patients already taking ICS in whom the diagnosis is uncertain, the ICS dose can be reduced by 25%-50% with review after 2-4 weeks to look for evidence of variable airflow limitation.

History and Symptoms

Features that increase the probability of asthma	Features that decrease the probability of asthma
More than one type of respiratory symptom: wheeze, shortness of breath, cough, and chest tightness	In adults, isolated cough with no other respiratory symptoms
Symptoms that are often worse at night or in the early morning	Chronic production of sputum
Symptoms that vary over time and in intensity	Shortness of breath associated with dizziness, light-headedness, or peripheral paresthesia
Symptoms triggered by viral infections, exercise, allergen exposure, changes in weather, laughter, or irritants such as car exhaust fumes, smoke, or strong smells	Chest pain
Exercise-related symptoms that worsen after exercise is stopped	Exercise-induced dyspnea with noisy inspiration; localized wheeze

Adapted from the GINA 2026 report.

• Other important elements of the history include age at onset, personal or family history of allergic disease, chronic rhinosinusitis and nasal polyps, reactions to aspirin or NSAIDs, occupational and environmental exposures, smoking and vaping, previous exacerbations and courses of OCS, and comorbidities such as gastroesophageal reflux disease, obesity, and inducible laryngeal obstruction.

Physical Examination

• The physical examination is often normal in patients with asthma.
• The most frequent abnormal finding is expiratory wheeze on auscultation, which may be absent or heard only on forced expiration.
• In severe exacerbations, wheeze may be absent because of severely reduced airflow ("silent chest").
• Crackles and inspiratory wheeze are not features of asthma and suggest an alternative diagnosis.
• The nose should be examined for signs of allergic rhinitis or nasal polyps.
• Signs of a severe or life-threatening exacerbation include inability to speak in sentences, respiratory rate >30/min, use of accessory muscles, agitation, drowsiness, confusion, and cyanosis.

Pulmonary Function Test

• Spirometry is the preferred method to document variable expiratory airflow limitation. FEV1/FVC is typically greater than 0.75-0.80 in healthy adults and greater than 0.90 in children.
• Before bronchodilator responsiveness testing, SABAs should be withheld for ≥4 hours, formoterol and salmeterol for 24 hours, indacaterol and vilanterol for 36 hours, and long-acting muscarinic antagonists for 36-48 hours. The bronchodilator test uses 200-400 mcg of salbutamol (albuterol), with repeat spirometry after 10-15 minutes.
• PEF meters can vary by up to 20%, so the same meter should be used, and the best of 3 readings should be recorded.

Test	Adults and adolescents	Children 6-11 years
Bronchodilator responsiveness	Increase in FEV1 or FVC ≥12% and ≥200 mL from baseline (greater confidence if ≥15% and ≥400 mL); if spirometry is not available, increase in PEF ≥20%	Increase in FEV1 ≥12% of predicted (or PEF ≥15%)
Excessive variability in twice-daily PEF over 2 weeks	Average daily diurnal PEF variability >10%	Average daily diurnal PEF variability >13%
Increase in lung function after 4 weeks of anti-inflammatory treatment	Increase in FEV1 ≥12% and ≥200 mL (or PEF ≥20%) from baseline, outside respiratory infections (adults)
Positive exercise challenge test	Fall in FEV1 >10% and >200 mL from baseline	Fall in FEV1 >12% of predicted (or PEF >15%)
Positive bronchial challenge test	Fall in FEV1 ≥20% with standard doses of methacholine, or ≥15% with standardized hyperventilation, hypertonic saline, or mannitol challenge	Fall in FEV1 ≥20% with methacholine
Excessive variation in lung function between visits	Variation in FEV1 ≥12% and ≥200 mL (or PEF ≥20%) between visits	Variation in FEV1 ≥12% (or PEF ≥15%) between visits

Criteria for confirming variable expiratory airflow limitation, adapted from the GINA 2026 report. Reduced FEV1/FVC should be documented at least once when FEV1 is low.

• GINA retains the bronchodilator responsiveness criterion of ≥12% and ≥200 mL, whereas the 2022 ERS/ATS technical standard defines a significant response as an increase of >10% of the predicted value for FEV1 or FVC.
• The joint BTS/NICE/SIGN guideline uses the following sequence of objective tests:

Step	Adults (17 years and older)	Children and young people (5-16 years)
1	Blood eosinophil count above the laboratory reference range or FeNO ≥50 ppb	FeNO ≥35 ppb
2	Bronchodilator responsiveness: FEV1 increase ≥12% and ≥200 mL from baseline, or ≥10% of the predicted normal value	Bronchodilator responsiveness: FEV1 increase ≥12% from baseline, or ≥10% of the predicted normal value
3	PEF variability ≥20% (twice daily for 2 weeks)	PEF variability ≥20%
4	Referral for bronchial challenge test (usually methacholine; fall in FEV1 of 20%)	Skin prick test to house dust mite, or total IgE and blood eosinophil count; diagnose asthma if sensitized or IgE is raised and eosinophils are >0.5 x 109/L; otherwise refer for a second opinion, including bronchial challenge testing

• In children under 5 years of age, the joint guideline recommends treating suspected asthma with ICS and reviewing the response, with objective tests attempted when the child reaches 5 years of age.

Bronchial Challenge Test

• Bronchial provocation testing with methacholine, histamine, exercise, eucapnic voluntary hyperventilation, hypertonic saline, or mannitol assesses airway hyperresponsiveness (see criteria above).
• These tests are moderately sensitive for asthma but have limited specificity, because airway hyperresponsiveness also occurs in allergic rhinitis, cystic fibrosis, bronchopulmonary dysplasia, and COPD. A negative test in a patient who is not taking ICS helps to exclude asthma.
• In adults, bronchial challenge testing is generally performed in secondary care when earlier tests are inconclusive.

Exhaled Nitric Oxide

• A FeNO level >50 ppb in adults and adolescents, or >35 ppb in children, supports the diagnosis of type 2 asthma, but lower levels do not rule out asthma.
• FeNO is also elevated in eosinophilic bronchitis, atopy, allergic rhinitis, and atopic dermatitis; it is typically not elevated in neutrophilic asthma, and it is lower in smokers and during bronchoconstriction.
• In a systematic review of 26 studies (4,518 participants), FeNO had a sensitivity of 0.65 (95% CI, 0.58-0.72), a specificity of 0.82 (95% CI, 0.76-0.86), a diagnostic odds ratio of 9.23 (95% CI, 6.55-13.01), and an area under the curve of 0.80 (95% CI, 0.77-0.85) for diagnosing asthma.
• The NAEPP suggests FeNO as an adjunct to the evaluation of patients 5 years and older when the diagnosis remains uncertain after history, examination, and spirometry (conditional recommendation, moderate certainty), and recommends against using FeNO alone to assess control, predict exacerbations, or assess exacerbation severity (strong recommendation, low certainty).
• The ATS supports FeNO for detecting eosinophilic airway inflammation, determining the likelihood of corticosteroid responsiveness, monitoring airway inflammation, and identifying possible nonadherence to corticosteroid therapy.

Laboratory Findings

• Blood eosinophil count: An eosinophil count above the laboratory reference range supports the diagnosis of type 2 asthma. Eosinophilia may also result from parasitic infection, atopic dermatitis, allergic rhinitis, chronic rhinosinusitis with nasal polyps, eosinophilic bronchitis, hypereosinophilic syndrome, and EGPA.
• Allergy testing: Skin prick testing is preferred, and allergen-specific IgE testing is an alternative. Sensitization does not necessarily mean that the allergen is causing symptoms, so results must be interpreted in the clinical context.
• Total serum IgE and Aspergillus-specific IgE: These tests are used to determine eligibility and dosing for anti-IgE therapy and to screen for ABPA (total IgE ≥500 IU/mL is a diagnostic criterion for ABPA).
• Sputum eosinophils: A sputum eosinophil count ≥2% indicates refractory type 2 inflammation in patients taking high-dose ICS.

Imaging

• Chest imaging is not routinely required for the diagnosis of asthma; it is used to exclude alternative diagnoses and complications.
• CT of the chest may show bronchiectasis, emphysema, nodules, airway wall thickening, and mucus plugging, and CT of the sinuses can assess chronic rhinosinusitis. Mucus plugs on CT are associated with eosinophilia and airflow obstruction.
• In ABPA, imaging findings consistent with the disease (such as bronchiectasis and mucus plugging) support the diagnosis.

Assessment of Control and Future Risk

• Asthma control is assessed in two domains: current symptom control and risk of future adverse outcomes. No single measure is adequate to assess control.

In the past 4 weeks, has the patient had:	Level of asthma symptom control
Daytime asthma symptoms more than twice a week?	Well controlled: none of these Partly controlled: 1-2 of these Uncontrolled: 3-4 of these
Any night waking due to asthma?
SABA reliever for symptoms more than twice a week?*
Any activity limitation due to asthma?

*Applies only to patients using a SABA reliever, not ICS-formoterol; excludes reliever taken before exercise. Adapted from the GINA 2026 Summary Guide.

• Validated questionnaires: The joint BTS/NICE/SIGN guideline recommends monitoring control with a validated questionnaire such as the Asthma Control Questionnaire (ACQ), the Asthma Control Test (ACT), or the Childhood Asthma Control Test (cACT), and does not recommend regular PEF monitoring unless there is a person-specific reason.
  • The ACT is a 5-item questionnaire with an internal consistency reliability of 0.84.
  • On the ACQ (scored 0-6), a score ≤0.75 indicates well-controlled asthma (negative predictive value 0.85), a score ≥1.50 indicates inadequately controlled asthma (positive predictive value 0.88), and the crossover point between the two is about 1.00.
  • GINA 2026 added the Peds-AIRQ for children 5-11 years of age and the Pediatric Respiratory Assessment Measure (PRAM) for assessing acute asthma in children.
• FeNO monitoring: FeNO monitoring may be considered in adults, and the NAEPP conditionally recommends FeNO as part of an ongoing monitoring strategy in patients with persistent allergic asthma.
• Blood eosinophils: In 130,248 patients with asthma, 20,929 (16%) had a blood eosinophil count >400 cells/µL; they had a higher rate of severe exacerbations (rate ratio 1.42; 95% CI, 1.36-1.47) and lower odds of achieving asthma control (OR 0.74).
• SABA overuse: In the SABINA cohort, use of 3-5, 6-10, and ≥11 SABA canisters per year was associated with a higher risk of exacerbation (HR 1.26, 1.44, and 1.77, respectively).

Outcome	Risk factors
Exacerbations	Uncontrolled asthma symptoms; SABA overuse (≥3 x 200-dose canisters per year; use of ≥1 canister per month increases the risk of death); inadequate ICS (not prescribed, poor adherence, or incorrect inhaler technique); obesity, chronic rhinosinusitis, gastroesophageal reflux disease, confirmed food allergy, and pregnancy; allergen exposure if sensitized, smoking, vaping, and air pollution; major psychological or socioeconomic problems; FEV1 <60% predicted and large bronchodilator responsiveness; higher blood eosinophil count or FeNO; ≥1 severe exacerbation in the past year; ever intubated or admitted to intensive care for asthma
Persistent airflow limitation	Preterm birth, low birth weight, and rapid infant weight gain; frequent productive cough; no ICS treatment in patients with severe exacerbations; exposure to tobacco smoke or noxious chemicals; low FEV1 at diagnosis; high blood eosinophil count
Medication side effects	Systemic: frequent OCS, long-term high-dose or potent ICS, and use of cytochrome P450 inhibitors such as ritonavir, ketoconazole, and itraconazole; local: high-dose ICS and poor inhaler technique

Adapted from the GINA 2026 Summary Guide.

Diagnostic Algorithm

Respiratory symptoms suggestive of asthma: wheeze, shortness of breath, chest tightness, or cough that vary over time and in intensity

History and physical examination; consider age-specific alternative diagnoses; test before starting ICS whenever possible

Spirometry with bronchodilator responsiveness testing

Variable expiratory airflow limitation confirmed (adults: FEV1 increase ≥12% and ≥200 mL)

Normal spirometry or no significant bronchodilator responsiveness

Diagnose asthma; assess symptom control, risk factors, comorbidities, and type 2 phenotype (blood eosinophils, FeNO, allergy testing); start ICS-containing treatment

FeNO and/or blood eosinophil count; PEF variability over 2 weeks; repeat spirometry when symptomatic

Still uncertain: bronchial challenge test in secondary care; a negative test in a patient not taking ICS makes asthma unlikely, so reconsider alternative diagnoses

Based on the GINA 2026 report, the ERS 2022 adult diagnostic guideline, and the 2024 BTS/NICE/SIGN guideline.

Treatment

Emergency Management | Medical Therapy | Alternative and Complementary Medicine | Bronchial Thermoplasty | Primary Prevention | Secondary Prevention | Cost-Effectiveness of Therapy | Future or Investigational Therapies

Initial Management

Goals and Principles

• The goals of treatment are good symptom control (few or no symptoms, no sleep disturbance, and unimpaired physical activity) and minimization of future risk (no exacerbations, stable lung function, no need for maintenance OCS, and no medication side effects).
• GINA strongly recommends that all adults, adolescents, children, and most preschool children with asthma receive ICS-containing treatment, and recommends against SABA-only treatment. Management follows a personalized Assess-Adjust-Review cycle.
• SABAs should not be prescribed to people of any age with asthma without a concomitant ICS.
• At the start of treatment, patients should receive training in inhaler technique, self-management education, and a written asthma action plan, and modifiable risk factors and comorbidities should be addressed. In a Cochrane review of 36 trials, self-management education with regular practitioner review reduced hospitalizations (relative risk [RR] 0.64; 95% CI, 0.50-0.82), emergency department visits (RR 0.82; 95% CI, 0.73-0.94), unscheduled visits (RR 0.68), days off work or school (RR 0.79), and nocturnal asthma (RR 0.67).

Initial Controller Treatment

• For patients 12 years and older with newly diagnosed asthma, the joint BTS/NICE/SIGN guideline recommends as-needed low-dose ICS-formoterol (AIR therapy). Patients who are highly symptomatic (for example, with regular nocturnal waking) or who present with a severe exacerbation should start low-dose MART.
• GINA prefers Track 1 (low-dose ICS-formoterol as the reliever) for adults and adolescents, starting at the step that matches the patient's symptoms and risk (see Medical Therapy).

Management of Acute Exacerbations

• Severity is assessed from speech, posture, alertness, respiratory rate, accessory muscle use, wheeze, air entry, oxygen saturation, and PEF. GINA 2026 strongly recommends a validated clinical score such as the PRAM in patients younger than 18 years.
• If the exacerbation occurs as part of anaphylaxis, epinephrine should be given first (intramuscular or intranasal).

Severity	Clinical features (age ≥6 years)	Initial treatment in primary care or the emergency department
Mild	Talks in sentences; can lie down; not agitated; respiratory rate normal or mildly increased; no or mild accessory muscle use; no or mild expiratory wheeze; normal air entry; SpO2 ≥94%; PEF >70%; PRAM 1-3	Salbutamol 4 puffs by pressurized metered-dose inhaler (pMDI) and spacer, or budesonide-formoterol 160/4.5 mcg 2 puffs (adults and adolescents; lower strengths are used in children); repeat once after 30-60 minutes if needed
Moderate	Talks in phrases; prefers sitting; not agitated; respiratory rate increased but ≤30/min; accessory muscle use; expiratory wheeze; decreased air entry; SpO2 ≥92%; PEF 50%-70%; PRAM 4-7	Salbutamol 4-6 puffs by pMDI and spacer (or 2.5 mg nebulized) up to 3 times, 20-30 minutes apart; ipratropium 4 puffs with salbutamol, up to 3 times; start OCS
Severe	Unable to speak, drink, or lie down; respiratory rate >30/min; silent or quiet chest; SpO2 <92%; PEF <50%; PRAM 8-12	Arrange transfer to acute care; salbutamol 6-10 puffs by pMDI and spacer (or 5 mg nebulized) every 20-30 minutes; ipratropium 4 puffs with each dose, up to 3 times; controlled oxygen to a target SpO2 of 92%-95%; systemic corticosteroids; close monitoring
Life-threatening	Drowsy, confused, or cyanosed; PRAM 11-12

One puff = salbutamol 100 mcg or ipratropium 20 mcg. Pulse oximetry may overestimate oxygen saturation in people with darker skin, and normal values are lower at high altitude. Adapted from the GINA 2026 Summary Guide.

• Inhaled SABA: A pMDI with a spacer is at least as effective as a nebulizer. In a Cochrane review, hospital admission rates were similar in adults (RR 0.94; 95% CI, 0.61-1.43) and children (RR 0.71; 95% CI, 0.47-1.08), and children treated with a spacer spent 33 minutes less in the emergency department. GINA 2026 recommends more conservative SABA doses, because SABA-induced lactic acidosis with compensatory hyperventilation can be misinterpreted as worsening asthma, and recommends reviewing the response after the first dose.
• ICS-formoterol: Budesonide-formoterol is an option for mild exacerbations in primary care or the emergency department in patients 6 years and older.
• Ipratropium bromide: Adding a short-acting anticholinergic to SABA reduced hospital admissions in adults (RR 0.72; 95% CI, 0.59-0.87; 65 fewer admissions per 1,000), with the greatest benefit in severe exacerbations, at the cost of more adverse effects (OR 2.03). In children, it reduced admissions from 23 to 17 per 100 (RR 0.73; 95% CI, 0.63-0.85; number needed to treat for benefit 16).
• Systemic corticosteroids: Corticosteroids given within 1 hour of emergency department presentation reduced hospital admissions (OR 0.40; 95% CI, 0.21-0.78; number needed to treat 8). Recommended doses are prednisolone 40-50 mg each morning for 5-7 days in adults, and 1-2 mg/kg/day (maximum 40 mg) for 3-5 days in children. In children, dexamethasone produced relapse rates similar to prednisone or prednisolone at 5 days (RR 0.90; 95% CI, 0.46-1.78) and at 10-14 days (RR 1.14; 95% CI, 0.77-1.67), with less vomiting in the emergency department (RR 0.29) and at home (RR 0.32).
• Oxygen: Oxygen is not recommended unless SpO2 is <92%, and the upper target is 95% in patients 6 years and older. In a randomized trial of 106 patients with severe exacerbations, high-concentration oxygen increased the proportion with a rise in transcutaneous carbon dioxide of ≥4 mmHg compared with oxygen titrated to 93%-95% (44% versus 19%; RR 2.3; 95% CI, 1.2-4.4).
• Intravenous magnesium sulfate: A single dose of 1.2 g or 2 g given over 15-30 minutes reduced hospital admissions in adults (OR 0.75; 95% CI, 0.60-0.92; 7 fewer admissions per 100). Limited evidence in children also suggests fewer admissions (OR 0.32; 95% CI, 0.14-0.74). Nebulized magnesium sulfate has only modest and uncertain benefit, and recent large trials found no clinically important benefit.
• Non-invasive ventilation: Evidence for non-invasive ventilation in respiratory failure due to severe asthma is scarce, and its use remains controversial.
• Lung function and discharge: Spirometry or PEF is strongly recommended during treatment (except in preschool children and life-threatening exacerbations) and before discharge. Discharge criteria after a mild exacerbation include ≥1-2 hours since the last dose of salbutamol, SpO2 ≥92% on room air, PEF improving and >70% of predicted or personal best, and adequate resources at home.
• Follow-up: Patients should be reviewed within 2-7 days (adults) or 2-5 days (children) and again within 2-3 months, and those who need more than 1 course of OCS per year should be referred. A single exacerbation is a red flag that should prompt review of maintenance treatment.

Acute Exacerbation Algorithm

Acute asthma exacerbation (age ≥6 years): assess speech, posture, alertness, respiratory rate, accessory muscle use, wheeze, SpO2, PEF, and PRAM score in children; if anaphylaxis, give epinephrine first

Mild or moderate: talks in sentences or phrases, respiratory rate ≤30/min, SpO2 ≥92%, PEF ≥50%

Severe or life-threatening: unable to speak, respiratory rate >30/min, SpO2 <92%, PEF <50%, silent chest, drowsiness, confusion, or cyanosis

Salbutamol by pMDI and spacer (mild: 4 puffs, or budesonide-formoterol 2 puffs; moderate: 4-6 puffs up to 3 times); moderate: add ipratropium and start OCS; oxygen only if SpO2 <92%

Arrange transfer to acute care; salbutamol 6-10 puffs or 5 mg nebulized every 20-30 minutes with ipratropium; oxygen to SpO2 92%-95%; systemic corticosteroids; consider IV magnesium sulfate

Review response after the first dose and within 1 hour; if improving, assess for discharge; if worsening, treat as severe

Monitor closely; drowsiness, confusion, or silent chest requires intensive care, where intubation may be needed

Before discharge: spirometry or PEF, SpO2 ≥92% on room air, PEF >70%, ICS-containing maintenance treatment, written action plan, inhaler technique check, OCS course if indicated; follow-up within 2-7 days (adults) or 2-5 days (children)

Based on the GINA 2026 report and Summary Guide.

Medical Therapy

Stepwise Treatment in Adults and Adolescents

• Treatment is adjusted up or down in a stepwise manner within a continuous Assess-Adjust-Review cycle. GINA Track 1, in which low-dose ICS-formoterol is the reliever, is preferred because it reduces severe exacerbations compared with SABA-based regimens and is simpler for patients.

Step	Track 1 (preferred)	Track 2 (alternative)
Step 1	As-needed low-dose ICS-formoterol (AIR-only)	As-needed low-dose ICS with SABA
Step 2		Daily low-dose maintenance ICS
Step 3	Low-dose maintenance ICS-formoterol (low-dose MART)	Low-dose maintenance ICS-LABA
Step 4	Medium-dose maintenance ICS-formoterol (medium-dose MART)	Medium-dose maintenance ICS-LABA
Step 5	Add-on LAMA; refer for phenotypic assessment; consider a trial of high-dose maintenance ICS-formoterol; anti-IgE, anti-interleukin 5 or 5 receptor, anti-interleukin 4 receptor alpha, or anti-TSLP biologic	As for Track 1, with a trial of high-dose ICS-LABA
Reliever	As-needed low-dose ICS-formoterol	As-needed ICS-SABA (or SABA if ICS-SABA is not available)

Adapted from the GINA 2026 Summary Guide.

Step	Budesonide-formoterol 160/4.5 mcg or beclomethasone-formoterol 100/6 mcg
Steps 1-2 (AIR-only)	1 inhalation whenever needed
Step 3 (low-dose MART)	1 inhalation morning and evening, plus 1 inhalation whenever needed
Step 4 (medium-dose MART)	2 inhalations morning and evening, plus 1 inhalation whenever needed

Patients should seek medical care if they need more than 12 total inhalations of budesonide-formoterol in a day (the maximum total daily dose of beclomethasone-formoterol is 8 inhalations). With Track 2, patients should seek care if they need ICS-SABA more than 6 times in any day, or a SABA again within 3 hours. Adapted from the GINA 2026 Summary Guide.

• The NAEPP prefers SMART at Steps 3 and 4 in patients 4 years and older (strong recommendation; high certainty in patients 12 years and older, moderate certainty in children 4-11 years), with a maximum of 8 puffs (36 mcg of formoterol) per day in children 4-11 years and 12 puffs (54 mcg of formoterol) per day in patients 12 years and older.
• The joint BTS/NICE/SIGN guideline escalates from AIR to low-dose MART and then to moderate-dose MART. If asthma remains uncontrolled despite good adherence, FeNO and blood eosinophils are measured: patients with raised levels are referred to a specialist, whereas those without raised levels receive an 8-12 week trial of a leukotriene receptor antagonist (LTRA) or LAMA, with referral if asthma remains uncontrolled after both. Patients using a SABA alone should be switched to AIR.

Anti-Inflammatory Reliever Therapy

• SYGMA 1: In mild asthma, the annualized rate of severe exacerbations was 0.20 with as-needed terbutaline, 0.07 with as-needed budesonide-formoterol, and 0.09 with maintenance budesonide (RR 0.36 [95% CI, 0.27-0.49] for budesonide-formoterol versus terbutaline; RR 0.83 [95% CI, 0.59-1.16] versus maintenance budesonide). Well-controlled weeks were 31.1%, 34.4%, and 44.4%, respectively, and median ICS exposure with as-needed budesonide-formoterol was 17% of that with maintenance budesonide (57 versus 340 mcg/day).
• SYGMA 2: As-needed budesonide-formoterol was noninferior to maintenance budesonide for severe exacerbations (annualized rates 0.11 versus 0.12; RR 0.97), with lower median ICS exposure (66 versus 267 mcg/day); the difference in ACQ-5 score (0.11) favored maintenance budesonide.
• Novel START: The annualized exacerbation rate was 0.195 with as-needed budesonide-formoterol, 0.400 with as-needed albuterol, and 0.175 with maintenance budesonide (RR 0.49 [95% CI, 0.33-0.72] versus albuterol; RR 1.12 [95% CI, 0.70-1.79] versus maintenance budesonide). Severe exacerbations occurred 9 times with budesonide-formoterol, compared with 23 times with albuterol (RR 0.40) and 21 times with maintenance budesonide (RR 0.44).
• PRACTICAL: In adults with mild to moderate asthma, as-needed budesonide-formoterol reduced severe exacerbations compared with maintenance budesonide plus as-needed terbutaline (0.119 versus 0.172 per patient per year; RR 0.69; 95% CI, 0.48-1.00).
• Cochrane review: Compared with a fast-acting beta2-agonist alone, as-needed combination ICS-formoterol reduced exacerbations requiring systemic steroids (OR 0.45; 95% CI, 0.34-0.60; 109 versus 52 per 1,000) and hospital admissions or emergency visits (OR 0.35; 95% CI, 0.20-0.60). Compared with regular ICS, it was associated with similar exacerbation rates (OR 0.79; 95% CI, 0.59-1.07), fewer hospital admissions or emergency visits (OR 0.63; 95% CI, 0.44-0.91), and lower ICS exposure (mean difference 154.51 mcg/day).
• MART: In a meta-analysis of 16 trials (22,748 patients), SMART reduced exacerbations in patients 12 years and older compared with the same dose of ICS-LABA (RR 0.68; 95% CI, 0.58-0.80) and with higher-dose ICS-LABA (RR 0.77; 95% CI, 0.60-0.98). In children 4-11 years, it reduced exacerbations compared with higher-dose ICS (RR 0.55; 95% CI, 0.32-0.94) and with the same dose of ICS-LABA (RR 0.38; 95% CI, 0.23-0.63).

ICS-SABA Reliever Therapy

• MANDALA: In moderate to severe asthma, as-needed albuterol-budesonide 180/160 mcg reduced the risk of a severe exacerbation by 26% compared with albuterol alone (HR 0.74; 95% CI, 0.62-0.89); the 180/80 mcg dose was associated with an HR of 0.84 (95% CI, 0.71-1.00).
• BATURA: Among 2,516 patients 12 years and older with uncontrolled mild asthma, as-needed albuterol-budesonide 180/160 mcg reduced severe exacerbations compared with albuterol alone (5.1% versus 9.1%; HR 0.53; 95% CI, 0.39-0.73; intention-to-treat 5.3% versus 9.4%; HR 0.54; 95% CI, 0.40-0.73). The annualized rate was 0.15 versus 0.32 (RR 0.47; 95% CI, 0.34-0.64), and the mean annualized systemic glucocorticoid dose was 23.2 versus 61.9 mg per year.
• PREPARE: In 1,201 Black and Latinx adults (603 Black and 598 Latinx), adding beclomethasone 80 mcg with each use of the reliever reduced the annualized rate of severe exacerbations (0.69 versus 0.82; HR 0.85; 95% CI, 0.72-0.999).
• For patients 12 years and older at Step 2, the NAEPP conditionally recommends either daily low-dose ICS with as-needed SABA, or as-needed concomitant ICS and SABA.

Long-Acting Bronchodilators

• LABA safety: LABAs must always be used together with an ICS. In a combined analysis of 4 safety trials involving 36,010 patients, serious asthma-related events occurred in 0.60% of patients receiving ICS and 0.66% of those receiving ICS-LABA (RR 1.09; 95% CI, 0.83-1.43), whereas exacerbations were less frequent with ICS-LABA (9.8% versus 11.7%; RR 0.83; 95% CI, 0.78-0.89).
• LAMA: Adding a LAMA to ICS reduced exacerbations compared with placebo (RR 0.67; 95% CI, 0.48-0.92), but LAMA was not superior to LABA as add-on therapy (RR 0.87; 95% CI, 0.53-1.42). The NAEPP conditionally recommends against adding a LAMA instead of a LABA to ICS, and conditionally recommends adding a LAMA to ICS-LABA in patients 12 years and older with uncontrolled persistent asthma.
• Triple therapy: In a meta-analysis of 20 trials (11,894 patients) with moderate to severe asthma, triple therapy (ICS-LABA-LAMA) reduced severe exacerbations compared with dual ICS-LABA therapy (22.7% versus 27.4%; RR 0.83; 95% CI, 0.77-0.90), with a small improvement in ACQ-7 score (-0.04) and no difference in quality of life or mortality; dry mouth and dysphonia were more common (3.0% versus 1.8%; RR 1.65). In the KALOS and LOGOS trials (4,311 treated patients 12-80 years of age, uncontrolled on medium- or high-dose ICS-LABA), budesonide-glycopyrronium-formoterol (glycopyrronium 28.8 mcg) improved trough FEV1 by 76 mL and FEV1 area under the curve by 90 mL compared with pooled budesonide-formoterol. It reduced severe exacerbations compared with pooled budesonide-formoterol (incidence rate ratio 0.86; 95% CI, 0.76-0.97) and with the current suspension formulation of budesonide-formoterol (0.82; 95% CI, 0.71-0.94), but not significantly compared with budesonide-formoterol in the same co-suspension inhaler (0.90; 95% CI, 0.78-1.03). GINA 2026 lists this triple combination at Step 5, noting that the reduction in exacerbations is smaller than with biologic therapy.

Other Add-On and Alternative Therapies

• Leukotriene receptor antagonists: As monotherapy, LTRAs were less effective than ICS, with more exacerbations requiring systemic corticosteroids (RR 1.51; 95% CI, 1.17-1.96; number needed to treat for one additional harm 28) and more hospital admissions (RR 3.33). In 2020, the U.S. Food and Drug Administration required a boxed warning for montelukast because of serious neuropsychiatric events, including agitation, depression, sleep problems, and suicidal thoughts or actions.
• Azithromycin: In adults with persistent symptomatic asthma despite ICS-LABA, azithromycin 500 mg three times a week for 48 weeks reduced exacerbations (1.07 versus 1.86 per patient-year; IRR 0.59; 95% CI, 0.47-0.74) and improved quality of life; patients with hearing impairment or prolonged QTc were excluded. The ERS/ATS guideline suggests a trial of macrolide therapy in adults with persistent symptoms or exacerbations despite high-dose ICS-LABA, irrespective of phenotype, and suggests adding tiotropium in severe asthma that remains uncontrolled despite GINA Step 4-5 or NAEPP Step 5 treatment.
• Short-term increase in ICS dose: In adults and adolescents, quadrupling the ICS dose when asthma control started to deteriorate reduced severe exacerbations (45% versus 52%; HR 0.81; 95% CI, 0.71-0.92). In children 5-11 years, quintupling the ICS dose did not reduce severe exacerbations (0.48 versus 0.37 per year; RR 1.3; 95% CI, 0.8-2.1) and may have been associated with slower linear growth (-0.23 cm per year; P=0.06). The NAEPP conditionally recommends against short-term increases in ICS dose in patients 4 years and older with mild to moderate persistent asthma who are likely to be adherent to daily ICS.
• Oral corticosteroid stewardship: Because OCS harms are cumulative, GINA emphasizes systemic corticosteroid stewardship for all patients with asthma.

Biologic Therapy for Severe Asthma

• Before biologic therapy is considered, the diagnosis should be confirmed, adherence and inhaler technique checked, comorbidities and modifiable risk factors managed, and high-dose ICS-LABA optimized.
• In patients taking high-dose ICS or daily OCS, refractory type 2 inflammation is suggested by a blood eosinophil count ≥150/µL, FeNO ≥20 ppb, sputum eosinophils ≥2%, or clinically allergen-driven asthma. Blood eosinophils and FeNO should be repeated up to 3 times before type 2 inflammation is excluded.
• The choice of biologic depends on quality-of-life impairment, baseline lung function, exacerbation frequency, baseline OCS use, endotype, biomarkers, and comorbidities; no head-to-head comparative trials are available.
• The ERS/ATS guideline suggests anti-interleukin 5 or 5 receptor therapy for adults with severe uncontrolled eosinophilic asthma, using a blood eosinophil cut-point of ≥150/µL to guide initiation; a blood eosinophil count ≥260/µL and FeNO ≥19.5 ppb to identify patients more likely to respond to anti-IgE therapy; and anti-interleukin 4/13 therapy for severe eosinophilic asthma, or for OCS-dependent severe asthma regardless of eosinophil count.

Biologic (target)	Eligibility criteria (GINA)	Dosing	Key evidence
Omalizumab and biosimilar omalizumab-igec (IgE)	Sensitization on skin prick testing or specific IgE; total serum IgE and body weight within the dosing range; exacerbations in the last year; age ≥6 years	Subcutaneous; dose and interval based on total serum IgE and body weight	Fewer exacerbations (OR 0.55; 95% CI, 0.42-0.60; 26% to 16%) and hospitalizations (OR 0.16; 95% CI, 0.06-0.42; 3% to 0.5%)
Mepolizumab (interleukin 5)	Exacerbations in the last year; blood eosinophils above a specified level (for example, ≥150/µL or ≥300/µL); age ≥12 years; also an option at Step 5 in children 6-11 years	100 mg subcutaneously every 4 weeks (40 mg every 4 weeks in children 6-11 years)	Exacerbations reduced by 53% (subcutaneous) and 47% (intravenous); median OCS dose reduction 50% versus 0% with placebo
Reslizumab (interleukin 5)	Exacerbations in the last year; blood eosinophilia; age ≥18 years	3.0 mg/kg intravenously every 4 weeks	In patients with eosinophils ≥400/µL, exacerbations reduced (RR 0.50; 95% CI, 0.37-0.67 and RR 0.41; 95% CI, 0.28-0.59 in two trials)
Benralizumab (interleukin 5 receptor alpha)	Exacerbations in the last year; blood eosinophilia; age ≥12 years	30 mg subcutaneously every 4 weeks for the first 3 doses, then every 8 weeks	In patients with eosinophils ≥300/µL, exacerbations reduced (RR 0.55 every 4 weeks; RR 0.49 every 8 weeks); median OCS dose reduction 75% versus 25% with placebo
Depemokimab (long-acting interleukin 5)	Severe eosinophilic asthma; age ≥12 years	100 mg subcutaneously every 26 weeks	Exacerbations reduced (0.46 versus 1.11; RR 0.42; 95% CI, 0.30-0.59 in SWIFT-1; 0.56 versus 1.08; RR 0.52; 95% CI, 0.36-0.73 in SWIFT-2)
Dupilumab (interleukin 4 receptor alpha)	Exacerbations in the last year with blood eosinophils ≥150/µL and ≤1500/µL, or FeNO ≥25 ppb, or need for maintenance OCS; age ≥12 years; also for severe eosinophilic or type 2 asthma in children 6-11 years	200 mg or 300 mg subcutaneously every 2 weeks; children 6-11 years: 100 mg (≤30 kg) or 200 mg (>30 kg) every 2 weeks	Exacerbations reduced by 47.7% overall and by 65.8% with eosinophils ≥300/µL; blood eosinophilia in 4.1% versus 0.6%; OCS dose reduced by 70.1% versus 41.9% with placebo
Tezepelumab (TSLP)	Exacerbations in the last year; age ≥12 years; no biomarker threshold required	210 mg subcutaneously every 4 weeks	Exacerbations reduced overall (0.93 versus 2.10; RR 0.44; 95% CI, 0.37-0.53) and with eosinophils <300/µL (RR 0.59; 95% CI, 0.46-0.75)

• In a Cochrane review of 17 trials with about 7,600 participants, anti-interleukin 5 therapies reduced clinically significant exacerbations: mepolizumab subcutaneous (RR 0.45; 95% CI, 0.36-0.55), reslizumab intravenous (RR 0.43; 95% CI, 0.33-0.55), and benralizumab subcutaneous (RR 0.59; 95% CI, 0.52-0.66), with modest improvements in FEV1 (0.08-0.15 L).
• Duration of trial: The response should be assessed after at least 4 months (6 months for depemokimab), and the trial extended to 6-12 months if the response is unclear.
• Switching: In the NIMBLE trial of patients responding to mepolizumab or benralizumab, switching to depemokimab did not meet noninferiority for exacerbations (0.57 versus 0.49 per year; RR 1.16; 95% CI, 0.98-1.38), although exacerbation rates remained low and asthma control and lung function were maintained. GINA 2026 states that switching to depemokimab may be considered for patients with a good response to mepolizumab, but not to benralizumab.

Biologic Selection Algorithm

Severe asthma: uncontrolled despite optimized high-dose ICS-LABA after confirming the diagnosis and addressing adherence, inhaler technique, and comorbidities

Assess type 2 biomarkers while on high-dose ICS or OCS: blood eosinophils, FeNO, and allergen sensitization (repeat up to 3 times)

Type 2 inflammation: blood eosinophils ≥150/µL, FeNO ≥20 ppb, sputum eosinophils ≥2%, or allergen-driven asthma

No evidence of type 2 inflammation

Choose according to eligibility criteria, biomarkers, comorbidities, and patient preference: anti-IgE, anti-interleukin 5 or 5 receptor, anti-interleukin 4 receptor alpha, or anti-TSLP

Consider anti-TSLP; non-biologic add-on options such as LAMA or azithromycin; review the diagnosis and comorbidities

Therapeutic trial for at least 4 months (6 months for depemokimab); extend to 6-12 months if the response is unclear; if there is no response, consider switching to a different biologic

Based on the GINA 2026 Difficult-to-Treat and Severe Asthma Guide.

Allergen Immunotherapy

• The European Academy of Allergy and Clinical Immunology (EAACI) recommends the house dust mite sublingual immunotherapy (SLIT) tablet as add-on therapy for adults with controlled or partly controlled house dust mite-driven allergic asthma (conditional recommendation, moderate-quality evidence), and subcutaneous immunotherapy (SCIT) for adults and children, and SLIT drops for children, with controlled house dust mite-driven asthma (conditional recommendation, low-quality evidence).
• In 834 adults with house dust mite allergic asthma, the SLIT tablet prolonged the time to the first moderate or severe exacerbation during ICS reduction (HR 0.72; 95% CI, 0.52-0.99 for 6 SQ-HDM; HR 0.69; 95% CI, 0.50-0.96 for 12 SQ-HDM).
• The NAEPP conditionally recommends SCIT as an adjunct to standard pharmacotherapy in patients 5 years and older with mild to moderate allergic asthma that is controlled at the initiation, build-up, and maintenance phases, and conditionally recommends against SLIT for the treatment of allergic asthma.

Procedural / Surgical Therapy

Bronchial Thermoplasty

• Bronchial thermoplasty is a bronchoscopic procedure that delivers thermal energy to the airway wall to reduce airway smooth muscle in adults with severe asthma.
• In the sham-controlled AIR2 trial of 288 adults, 79% of treated patients and 64% of sham-treated patients had a clinically meaningful improvement in the Asthma Quality of Life Questionnaire score (≥0.5). In the post-treatment period, thermoplasty reduced severe exacerbations, emergency department visits, and days missed from work or school, but 6% more treated patients were hospitalized during the treatment period.
• In BT10+, 192 of 429 patients from three randomized trials were followed for a median of 12.1 years. Among the 136 participants treated with thermoplasty, the proportion with severe exacerbations was 25% (34 of 136) at 10 years or more, compared with 24% (33 of 135) at 1 year and 22% (28 of 130) at 5 years, and spirometry remained stable. Bronchiectasis was found in 13 of 97 patients (13%) on CT and was new in 6 of 89 patients (7%).
• The NAEPP conditionally recommends against bronchial thermoplasty in adults with persistent asthma; patients who still choose it should be treated within a clinical trial or registry. The ERS/ATS guidelines similarly recommend that it be performed only in the context of an independent systematic registry or a clinical study.

Airway Management in Life-Threatening Asthma

• Patients with severe or life-threatening exacerbations require urgent transfer to acute care, and those with drowsiness, confusion, or a silent chest may need intensive care, including endotracheal intubation and mechanical ventilation.

Long-Term Management

• Review and adjustment: Patients should be reviewed 8-12 weeks after any change in treatment and at least annually. Stepping down should be discussed at the annual review, with at least 8-12 weeks between dose reductions; patients 12 years and older can be considered for stepping down to AIR therapy.
• Before stepping up: Inhaler technique, adherence, comorbidities, and exposures should be checked before treatment is increased. In the CRITIKAL study of 3,660 patients, insufficient inspiratory effort occurred in 32%-38% of dry powder inhaler users and was associated with uncontrolled asthma (adjusted OR 1.30 [95% CI, 1.08-1.57] with Turbohaler and 1.56 [95% CI, 1.17-2.07] with Diskus), and actuation before inhalation with metered-dose inhalers (24.9%) was associated with uncontrolled asthma (adjusted OR 1.55; 95% CI, 1.11-2.16). GINA 2026 advises shaking the pMDI immediately before each actuation.
• Self-management: Every patient should have self-management education and a written asthma action plan.
• Environmental control: The NAEPP conditionally recommends against routine allergen mitigation in patients who are not sensitized to the allergen; for sensitized patients with symptoms, it conditionally recommends multicomponent allergen-specific interventions, including integrated pest management, with mite-impermeable covers used only as part of a multicomponent intervention.
• Smoking and vaping: Patients and families should be supported to stop smoking and vaping and to avoid environmental tobacco smoke.
• Occupational asthma: Early diagnosis and appropriate intervention are associated with a better prognosis, and patients with suspected occupational asthma should be referred to a specialist.
• Vaccination: Inactivated influenza vaccine did not cause a clinically important increase in asthma exacerbations in the 2 weeks after vaccination (risk difference 0.014; 95% CI, -0.010 to 0.037), although the evidence on protection against influenza-related exacerbations is uncertain.
• Weight management: GINA 2026 reviews observational data on glucagon-like peptide-1 receptor agonists in patients with asthma and obesity.
• Treatment goal of remission: Clinical remission (see Natural History) is increasingly used as a long-term treatment goal, particularly in severe asthma treated with biologics.
• Primary prevention: Reducing exposure to tobacco smoke and air pollution is important for preventing asthma. GINA 2026 notes interest in maternal respiratory syncytial virus immunization and nirsevimab for their possible effect on childhood asthma.

Special Populations

Children 6-11 Years

Step	GINA treatment options for children 6-11 years
Step 1	As-needed low-dose ICS-formoterol, or low-dose ICS taken whenever SABA is taken
Step 2	Daily low-dose maintenance ICS
Step 3	Medium-dose ICS, low-dose ICS-LABA, or low-dose MART
Step 4	Medium-dose ICS-LABA or low-dose MART (the Step 4 MART maintenance dose is double that at Step 3 but remains a low daily ICS dose); refer for expert advice
Step 5	Refer for phenotypic assessment; higher-dose ICS-LABA or add-on therapy (LAMA, anti-IgE, anti-interleukin 4 receptor alpha, or anti-interleukin 5)
Reliever	As-needed ICS-formoterol (for patients on AIR or MART), ICS-SABA, or SABA
Other options	Daily LTRA, low-dose ICS plus LTRA, or add-on tiotropium or LTRA (LTRAs carry a warning about neuropsychiatric adverse effects)

Adapted from the GINA 2026 Summary Guide.

• GINA 2026 bases the use of as-needed budesonide-formoterol in children 6-11 years on the CARE study.
• The joint BTS/NICE/SIGN guideline recommends paediatric low-dose ICS with as-needed SABA for children 5-11 years, followed by paediatric low-dose MART and then moderate-dose MART. Children who cannot manage MART can receive an 8-12 week trial of an LTRA, followed by low-dose and then moderate-dose ICS-LABA, before referral.
• In 341 children 4-11 years of age, budesonide-formoterol maintenance and reliever therapy reduced exacerbations by 70%-79% compared with fixed-dose regimens (0.08 versus 0.28 and 0.40 exacerbations per patient), and children receiving it grew 1.0 cm more than those receiving higher-dose budesonide.
• In 408 children 6-11 years with uncontrolled moderate to severe asthma, dupilumab 100 mg (≤30 kg) or 200 mg (>30 kg) every 2 weeks reduced severe exacerbations in the type 2 population (blood eosinophils ≥150/µL or FeNO ≥20 ppb) from 0.75 to 0.31 per year (59.3% reduction; 95% CI, 39.5-72.6) and improved percent-predicted FEV1 by 5.2 points (95% CI, 2.1-8.3).
• In 290 urban children 6-17 years with exacerbation-prone eosinophilic asthma (≥2 exacerbations in the previous year and blood eosinophils ≥150/µL), mepolizumab reduced exacerbations (0.96 versus 1.30 per year; RR 0.73; 95% CI, 0.56-0.96).
• Childhood ICS use was associated with a 1.2 cm reduction in adult height, which was not progressive or cumulative; the lowest effective ICS dose should therefore be used.

Children 5 Years and Younger

• Most preschool children with asthma should receive ICS-containing treatment.
• The joint BTS/NICE/SIGN guideline recommends an 8-12 week trial of twice-daily paediatric low-dose ICS with as-needed SABA, stopping treatment and reviewing the child if symptoms resolve, restarting it if symptoms recur, trialling an LTRA if asthma is uncontrolled on moderate-dose ICS, and referring the child for specialist assessment if needed. Children with a hospital admission, or 2 or more emergency attendances with wheeze in 12 months, should be referred.
• For children 0-4 years with recurrent wheezing triggered by respiratory tract infections (≥3 episodes in their lifetime or 2 in the past year), the NAEPP conditionally recommends a short course of daily ICS (7-10 days) started at the onset of a respiratory tract infection, together with as-needed SABA (high certainty of evidence).
• In 129 children 1-6 years of age, preemptive high-dose fluticasone (750 mcg twice daily for up to 10 days from the onset of an upper respiratory tract infection) reduced the need for rescue OCS (8% versus 18%; OR 0.49; 95% CI, 0.30-0.83), but was associated with smaller gains in height and weight.
• In a crossover trial of 300 children 12-59 months of age with persistent asthma, 74% of those with analyzable data (170 of 230) had a differential response to daily ICS, as-needed ICS, or daily LTRA. Daily ICS was most often the best treatment, and a better response to daily ICS was predicted by aeroallergen sensitization, especially with a blood eosinophil count ≥300/µL.
• In 700 children 10-60 months of age with virus-induced wheezing presenting to hospital, oral prednisolone did not shorten the duration of hospitalization compared with placebo (11.0 versus 13.9 hours; ratio of geometric means 0.90; 95% CI, 0.77-1.05).

Adolescents

• Adolescents should be asked about smoking and vaping, inhaler use at school, and career choices that may involve work-related exposures.

Pregnancy

• Exacerbations requiring medical intervention occur in about 20% of pregnant women with asthma, and about 6% are admitted to hospital. Exacerbations occur mainly in the late second trimester and are commonly triggered by viral infections and nonadherence to ICS. Severe exacerbations are associated with low birth weight, and ICS use may reduce the risk of exacerbations.
• In 220 pregnant women, FeNO-guided treatment (ICS increased when FeNO was >29 ppb and decreased when it was <16 ppb) reduced exacerbations (0.288 versus 0.615 per pregnancy; IRR 0.496; 95% CI, 0.325-0.755; number needed to treat 6) and neonatal hospitalizations (8% versus 17%).
• Asthma should be reviewed early in pregnancy and after delivery. SABAs, LABAs, ICS, and oral theophyllines should be used as normal during pregnancy and breastfeeding; OCS should be offered for exacerbations; and LTRAs or LAMAs should not be stopped if they are needed for asthma control. Smoking cessation should be supported.

Older Adults

• In older adults, the differential diagnosis includes COPD, cardiac failure, medication-related cough, and parenchymal lung disease, and asthma and COPD may coexist. In the United States, the asthma death rate in 2021 was highest among adults ≥65 years of age (27.1 per million).

Exercise-Induced Bronchoconstriction

• A SABA taken before exercise is recommended for all patients with exercise-induced bronchoconstriction. If symptoms persist, a daily ICS, a daily LTRA, or a mast cell stabilizer before exercise is recommended (strong recommendations).

Occupational Asthma

• Work-related asthma should be considered in all patients with new-onset or worsening asthma, and evaluation may include serial PEF measurements at and away from work, methacholine challenge, immunologic tests, and specific inhalation challenge.

NSAID-Exacerbated Respiratory Disease

• N-ERD should be suspected in patients with asthma and/or chronic rhinosinusitis with nasal polyps who react to aspirin or other NSAIDs. The diagnosis is based on the history and, when it is uncertain, aspirin provocation testing; affected patients should avoid NSAIDs that inhibit cyclooxygenase-1, and aspirin desensitization followed by daily aspirin is an option for selected patients.

Allergic Bronchopulmonary Aspergillosis

• Acute ABPA is treated with prednisolone or itraconazole monotherapy, with combination therapy reserved for recurrent exacerbations; routine treatment of asymptomatic ABPA is not recommended.

Racial and Ethnic Minority Populations

• In the United States, asthma prevalence is highest among American Indian or Alaska Native and Black non-Hispanic people, and the asthma death rate among Black non-Hispanic people (24.4 per million) is more than twice that among White non-Hispanic people (9.8 per million). In Black and Latinx adults, reliever-triggered ICS reduced severe exacerbations (see ICS-SABA Reliever Therapy).

Low-Resource Settings

• In 2023, bronchodilators were available in public primary health care facilities in fewer than two-thirds of low- and lower-middle-income countries, and steroid inhalers in fewer than half. A homemade spacer made from a 500 mL plastic bottle can be as effective as a commercially manufactured spacer.

Case Studies

Case #1

Related Chapters

• Exercise Induced Asthma
• Occupational Asthma
• Nocturnal Asthma
• Asthma and GERD
• Aspirin Induced Asthma
• Asthma In Pregnancy