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WikiDoc Resources for Long COVID


Most recent articles on Long COVID

Most cited articles on Long COVID

Review articles on Long COVID

Articles on Long COVID in N Eng J Med, Lancet, BMJ


Powerpoint slides on Long COVID

Images of Long COVID

Photos of Long COVID

Podcasts & MP3s on Long COVID

Videos on Long COVID

Evidence Based Medicine

Cochrane Collaboration on Long COVID

Bandolier on Long COVID


Clinical Trials

Ongoing Trials on Long COVID at Clinical Trials.gov

Trial results on Long COVID

Clinical Trials on Long COVID at Google

Guidelines / Policies / Govt

US National Guidelines Clearinghouse on Long COVID

NICE Guidance on Long COVID





Books on Long COVID


Long COVID in the news

Be alerted to news on Long COVID

News trends on Long COVID


Blogs on Long COVID


Definitions of Long COVID

Patient Resources / Community

Patient resources on Long COVID

Discussion groups on Long COVID

Patient Handouts on Long COVID

Directions to Hospitals Treating Long COVID

Risk calculators and risk factors for Long COVID

Healthcare Provider Resources

Symptoms of Long COVID

Causes & Risk Factors for Long COVID

Diagnostic studies for Long COVID

Treatment of Long COVID

Continuing Medical Education (CME)

CME Programs on Long COVID


Long COVID en Espanol

Long COVID en Francais


Long COVID in the Marketplace

Patents on Long COVID

Experimental / Informatics

List of terms related to Long COVID

For COVID-19 main page, click here For COVID-19 frequently asked inpatient questions, click here For COVID-19 frequently asked outpatient questions, click here

Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Mitra Chitsazan, M.D.[2] Edzel Lorraine Co, DMD, MD[3]

Synonyms and keywords: Long COVID Syndrome, long COVID, long-haul COVID, post-COVID-19 condition, post-COVID-19 syndrome, post-acute sequelae of COVID-19 (PASC), chronic COVID syndrome (CCS), Long-hauler COVID-19, Long-tail COVID, Long-haulers, Post-acute COVID-19 syndrome, Acute post-COVID symptoms, Long post-COVID symptoms, Persistent post-COVID symptoms, Post-acute COVID-19, On-going symptomatic COVID-19, Chronic COVID-19


Shortly after the COVID-19 pandemic onset, emerging studies showed that a considerable proportion of patients with COVID-19 might exhibit sustained postinfection sequelae. This condition has been defined by a variety of names, including long COVID or long-haul COVID, and post-COVID-19 condition. The absence of a universally standardized terminology has made characterization of the epidemiology, risk factors, clinical characteristics, and potential treatments options difficult. Symptoms may occur as an unpredictable combination of respiratory, cardiovascular, urological, neurological, and/or gastrointestinal manifestations. However, the most common symptoms include fatigue, dyspnea, and cognitive dysfunction (known as brain fog by the patients). Symptoms may begin following initial recovery from an acute COVID-19 episode or may persist from the initial acute episode. Symptoms might also fluctuate or relapse over time.

Historical Perspective


  • On October 6, 2021, World Health Organization (WHO) released a clinical case definition of the post-COVID-19 condition through a robust, protocol-based methodology (Delphi consensus), which engaged a diverse group of representative patients, patient-researchers, external experts, WHO staff, and other stakeholders from multiple geographies. [3] It was acknowledged that this definition may change with emerging new evidence and continuously evolving our understanding of the consequences of COVID-19.
  • According to WHO clinical case definition, the post-COVID-19 condition is defined as: [3]
Source Terms Definition
WHO [3] Post-COVID-19 condition
CDC [4] Long COVID
  • While most persons with COVID-19 recover and return to normal health, some patients can have symptoms that can last for weeks or even months after recovery from acute illness.
  • Even people who are not hospitalized and who have a mild illness can experience persistent or late symptoms."
Nature [5] Post-acute COVID-19
Lancet [6] Long COVID
  • Multiorgan symptoms after COVID-19 are being reported by increasing numbers of patients.
  • They range from cough and shortness of breath to fatigue, headache, palpitations, chest pain, joint pain, physical limitations, depression, and insomnia, and affect people of varying ages.
  • At the Lancet–Chinese Academy of Medical Sciences conference on 23 November 2020, Bin Cao presented data (in press at the Lancet) on the long-term consequences of COVID-19 for patients in Wuhan and warned that dysfunctions and complications could persist in some discharged patients for at least 6 months.
  • So-called long COVID is a burgeoning health concern and action is needed now to address it.
Nice [7] Long COVID
Scientific American [8] Long Haul COVID
  • Individuals whose symptoms persist or develop outside the initial viral infection, but the duration and pathogenesis are unknown.
Royal Society [9] Long COVID
Haute Autorité de santé, France [10] Long COVID
  • Three criteria:
    • Having presented with symptomatic form of COVID-19
    • Presenting with one or more initial symptoms 4 weeks after the start of the disease
    • None of these symptoms can be explained by another diagnosis


There is no established system for the classification of long COVID.


The exact pathogenesis of long COVID is not fully understood. A controlled study found no unique abnormalities[11] However, a number of putative pathophysiologic mechanisms have been suggested.

Cytokines and Biomarkers

Epidemiology and Demographics

A cohort study found the COVID alpha variant found[39]:

  • "Persistent symptoms in COVID-19-positive participants at 90-150 days after COVID-19 compared with before COVID-19 and compared with matched controls included chest pain, difficulties with breathing, pain when breathing, painful muscles, ageusia or anosmia, tingling extremities, lump in throat, feeling hot and cold alternately, heavy arms or legs, and general tiredness."
  • "In 12·7% of patients, these symptoms could be attributed to COVID-19, as 381 (21·4%) of 1782 COVID-19-positive participants versus 361 (8·7%) of 4130 COVID-19-negative controls had at least one of these core symptoms substantially increased to at least moderate severity at 90-150 days after COVID-19 diagnosis or matched timepoint."

Risk Factors


There is insufficient evidence to recommend routine screening for long COVID.

Natural History, Complications, and Prognosis

  • The natural history, clinical course, long-term complications, and prognosis of long COVID-19 are still not completely understood.
  • Manifestations of the post-COVID-19 condition vary considerably in terms of organ involvement and severity of symptoms; however, they generally impact the everyday functioning of affected patients. [3]
  • Symptoms might newly develop following initial recovery from an acute COVID-19 illness or occur as a persist from the initial episode. [3]
  • Symptoms might also fluctuate or relapse over time. [3]


Diagnostic Study of Choice

History and Symptoms

Long COVID can involve almost every organ. The most common symptoms of long COVID include: [3] [37] [41] [42]

Physical Examination

Laboratory Findings

There are no diagnostic laboratory findings associated with long COVID. Symptoms do not correlate with the serology of SARS-CoV-2.


In patients with cardiopulmonary symptoms, an ECG may be needed.


A chest x-ray may be helpful in the diagnosis of pulmonary complications of COVID-19 such as lung damage (ie, ground glass opacities, consolidation, interlobular septal thickening) and pleural effusion.

Echocardiography or Ultrasound

In selected patients with cardiopulmonary symptoms, echocardiography may be necessary.

CT scan

In patients with cardiopulmonary symptoms, a chest CT scan may be needed.


There are no MRI findings associated with long COVID. However, a cardiac MRI may be helpful in the diagnosis of myocarditis in COVID-19 patients.

Other Imaging Findings

There are no other imaging findings associated with long COVID.

Other Diagnostic Studies

In selected patients with cardiopulmonary symptoms, Holter monitoring, cardiopulmonary exercise testing (CPET), and pulmonary function tests may be necessary.


Due to the diversity of symptoms and their severity, the mainstay of long COVID treatment is multidisciplinary and supportive. The management should focus on supporting self-management and individualized rehabilitation. [43] [44]

Medical Therapy

  • Alopecia
    • There is no specific therapy for alopecia in COVID-19 patients, and it should be managed similarly to non-COVID-19 patients.
    • In patients with concomitant malnutrition, nutritional deficiencies should be corrected.

Primary Prevention

The most effective measure to prevent the post-COVID-19 condition is to prevent COVID-19. These primary prevention strategies include:

Secondary Prevention

There are no established measures for the secondary prevention of long COVID.


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