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{{CMG}}; '''Assistant Editor-In-Chief:''' Taylor Palmieri
{{CMG}}; '''Assistant Editor-In-Chief:''' [[User:YazanDaaboul|Yazan Daaboul]], [[User:Sergekorjian|Serge Korjian]], Taylor Palmieri


==Overview==
==Overview==
'''Hypertension''', commonly referred to as "'''high blood pressure'''" or '''HTN''', is a medical condition in which the [[blood pressure]] is chronically elevated.<ref>{{KMLEref|hypertension|07-04-17}}</ref> While it is formally called '''arterial hypertension''', the word "hypertension" without a qualifier usually refers to [[artery|arterial]] hypertension.
Arterial blood pressure (BP) is a measure of the force exerted by the blood on the arterial walls. It is the function of both the cardiac output (CO) and the systemic vascular resistance (SVR). The maintenance of a normal blood pressure value is crucial to ensure appropriate blood circulation throughout the cardiovascular system. Arterial BP is considered one of the most important vital signs in the clinical setting.
 
Hypertension (HTN) is generally defined as an elevated systolic blood pressure (SBP) ≥ 140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg at each of two or more visits.<ref name="pmid16512265">{{cite journal| author=Cuddy ML| title=Treatment of hypertension: guidelines from JNC 7 (the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure 1). | journal=J Pract Nurs | year= 2005 | volume= 55 | issue= 4 | pages= 17-21; quiz 22-3 | pmid=16512265 | doi= | pmc= |url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16512265 }} </ref> However, target BP values are set at a lower threshold in specific populations, such as diabetics and subjects with significant proteinuria and other renal diseases.


==Classification==
==Classification==
The Joint National Committee seventh report (JNC 7) defines hypertension as a [[systolic blood pressure]] of over 140 mm Hg or a [[diastolic blood pressure]] greater than 90 mm Hg based upon the average of two or more properly measured readings at each of two or more visits after an initial screen<ref name="pmid12748199">{{cite journal| author=Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL et al.| title=The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. | journal=JAMA | year= 2003 | volume= 289 | issue= 19 | pages= 2560-72 | pmid=12748199 | doi=10.1001/jama.289.19.2560 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12748199  }} </ref>. Hypertension can be classified as either '''essential''' (primary) or '''secondary'''. Essential hypertension indicates that no specific medical cause can be found to explain a patient's condition. [[Secondary hypertension]] indicates that the high blood pressure is a result of (i.e. secondary to) another condition, such as [[kidney disease]] or certain [[tumor]]s (especially of the [[adrenal gland]]).
In 2004, the Seventh Report of the Joint National Committee (JNC 7) classified blood pressure values into 4 categories: normal, prehypertension, stage I hypertension, and stage II hypertension.<ref name="pmid16512265">{{cite journal| author=Cuddy ML| title=Treatment of hypertension: guidelines from JNC 7 (the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure 1). | journal=J Pract Nurs | year= 2005 | volume= 55 | issue= 4 | pages= 17-21; quiz 22-3 | pmid=16512265 | doi= | pmc= |url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16512265 }} </ref> In 2007, the Task Force for the Management of Arterial Hypertension of the European Society of Hypertension (ESH) and the European Society of Cardiology (ESC) classified blood pressure into 7 categories.<ref name="pmid18327095">{{cite journal|author=Bonny A, Lacombe F, Yitemben M, Discazeaux B, Donetti J, Fahri P et al.| title=The 2007 ESH/ESC guidelines for the management of arterial hypertension. | journal=J Hypertens | year= 2008 |volume= 26 | issue= 4 |pages= 825; author reply 825-6 | pmid=18327095 | doi=10.1097/HJH.0b013e3282f857e7 |pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=18327095 }} </ref> This classification remained unchanged in the 2013 ESH/ESC classification.<ref name="pmid23817082">{{cite journal|author=Mancia G, Fagard R, Narkiewicz K, Redón J, Zanchetti A, Böhm M et al.| title=2013 ESH/ESC Guidelines for the management of arterial hypertension: the Task Force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC). | journal=J Hypertens | year= 2013 | volume= 31 | issue= 7 | pages= 1281-357 |pmid=23817082 | doi=10.1097/01.hjh.0000431740.32696.cc | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=23817082 }}</ref> The ESH/ESC classification excludes JNC 7’s pre-hypertension category, but includes 3 different grades of hypertension in contrast to JNC 7’s two-stage classification of hypertension.


==Pathophysiology==
==Pathophysiology==
Although the pathophysiology of secondary [[hypertension]] is known, there is still much debate about the true pathogenesis of primary (essential) hypertension. It is now conceded that hypertension is caused by multiple [[genetic]] and environmental factors with varying roles between individuals <ref name="pmid16512265">{{cite journal| author=Cuddy ML| title=Treatment of hypertension: guidelines from JNC 7 (the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure 1). | journal=J Pract Nurs | year= 2005 | volume= 55 | issue= 4 | pages= 17-21; quiz 22-3 | pmid=16512265 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16512265  }} </ref>.
Although the pathophysiology of secondary [[hypertension]] has been outlined, there is still much debate about the true pathogenesis of primary (essential) hypertension. It is now conceded that hypertension is caused by multiple [[genetic]] and environmental factors with varying roles between individuals.<ref name="pmid16512265">{{cite journal| author=Cuddy ML| title=Treatment of hypertension: guidelines from JNC 7 (the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure 1). | journal=J Pract Nurs | year= 2005 | volume= 55 | issue= 4 | pages= 17-21; quiz 22-3 | pmid=16512265 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16512265  }} </ref>
 
==Causes==
==Causes==
The prevalence of [[primary hypertension]] is much more common than [[secondary hypertension]], where only 5-10% of hypertension cases are diagnosed as secondary hypertension<ref name="pmid12537168">{{cite journal| author=Onusko E| title=Diagnosing secondary hypertension. | journal=Am Fam Physician | year= 2003 | volume= 67 | issue= 1 | pages= 67-74 | pmid=12537168 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12537168  }} </ref>. When a full evaluation yields no clear etiology for the hypertension, the latter is thus identified as primary or essential hypertension. It is considered a chronic disease that requires lifetime treatment and management. If an underlying disease is identifiable as the cause of hypertension, the latter is called secondary hypertension. Causes of secondary hypertension include [[obstructive sleep apnea]], [[hyperaldosteronism]], [[kidney disease]]s, excess [[catecholamine]]s, [[coarctation]], [[cushing syndrome]] among other diseases.
The prevalence of [[primary hypertension]] is much more common than [[secondary hypertension]], where only 5-10% of hypertension cases are diagnosed as secondary hypertension<ref name="pmid12537168">{{cite journal| author=Onusko E| title=Diagnosing secondary hypertension. | journal=Am Fam Physician | year= 2003 | volume= 67 | issue= 1 | pages= 67-74 | pmid=12537168 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12537168  }} </ref>. When a full evaluation yields no clear etiology for the hypertension, the latter is thus identified as primary or essential hypertension. It is considered a chronic disease that requires lifetime treatment and management. If an underlying disease is identifiable as the cause of hypertension, the latter is called secondary hypertension. Causes of secondary hypertension include [[obstructive sleep apnea]], [[hyperaldosteronism]], [[kidney disease]]s, excess [[catecholamine]]s, [[coarctation]], [[cushing syndrome]] among other diseases.
{{Familytree/start}}
{{Familytree | | | A01 | | A01= '''[[Chronic hypertension]]'''}}
{{Familytree | |,|-|^|-|.| }}
{{Familytree | B01 | | B02 | B01='''[[Primary hypertension]]''' <br>(also known as [[essential hypertension]]) <br> (95% of the cases)| B02= '''[[Secondary hypertension]]'''<br> <br> (5% of the cases)}}
{{Familytree/end}}
==Differentiating Hypertension from other Diseases==
==Differentiating Hypertension from other Diseases==
Sustained hypertension should be distinguished from benign entities such as white coat hypertension.
Before the diagnosis of primary (essential) hypertension, secondary causes of hypertension should be ruled out. Additionally, other conditions that may elevate BP include: White coat hypertension, masked hypertension, and pseudohypertension.


==Epidemiology and Demographics==
==Epidemiology and Demographics==
Hypertension is one of the most common diseases afflicting humans worldwide, estimated to have a prevalence of as many as 1 billion individuals, and causing 7.1 million deaths per year.<ref name="pmid14656957">{{cite journal| author=Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL et al.| title=Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. | journal=Hypertension | year= 2003 | volume= 42 | issue= 6 | pages= 1206-52 | pmid=14656957 | doi=10.1161/01.HYP.0000107251.49515.c2 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14656957  }} </ref> Hypertension is the most important modifiable risk factor for [[coronary heart disease]] (the leading cause of death in North America), [[stroke]] (the third leading cause), [[congestive heart failure]], [[peripheral vascular disease]], and is a leading cause of [[chronic renal failure]]. Despite the prevalence and associated complications of hypertension, control of the disease is still exceedingly insufficient.
Hypertension is considered an epidemic worldwide. It continues to be one of the most common diseases. In October 2013, CDC data from the 2011-2012 National Health And Nutrition Examination Survey (NHANES) demonstrated that the overall age-adjusted prevalence of hypertension among U.S. adults aged 18 and older was 29.1%.<ref name="pmid24171916">{{cite journal| author=Nwankwo T, Yoon SS, Burt V, Gu Q| title=Hypertension among adults in the United States: national health and nutrition examination survey, 2011-2012. | journal=NCHS Data Brief | year= 2013 | volume= | issue= 133 | pages= 1-8| pmid=24171916 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=24171916 }} </ref> Similar surveys conducted in Europe estimated the prevalence of hypertension to be 44%.<ref name="pmid12746359">{{cite journal| author=Wolf-Maier K, Cooper RS, Banegas JR, Giampaoli S, Hense HW, Joffres M et al.|title=Hypertension prevalence and blood pressure levels in 6 European countries, Canada, and the United States. | journal=JAMA | year= 2003 | volume= 289 | issue= 18 | pages= 2363-9 |pmid=12746359| doi=10.1001/jama.289.18.2363 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12746359 }} </ref> The prevalence of hypertension increases among older patients and among non-Hispanic black patients, but is similar in both genders.


==Risk Factors==
==Risk Factors==
Established risk factors for essential hypertension include increased [[alcohol]] intake (more than 2 drinks per day), increased salt intake in diet (more than 2 gm per day), [[obesity]], and a sedentary lifestyle and lack of [[exercise]].   All these risk factor are reversible.  [[Smoking]] is not a risk factor for hypertension.
Established risk factors for essential hypertension include old age, male gender, African American ethnicity, dyslipidemia, diabetes mellitus, smoking, increased salt intake in diet, obesity, and sedentary lifestyle. Studies are currently assessing the role of new emerging factors that might be considered as new risk factors for the development of hypertension.
 
==Screening==
==Screening==
The Joint National Committee seventh report (JNC 7) defines hypertension as a [[systolic blood pressure]] of over 140 mm Hg or a [[diastolic blood pressure]] greater than 90 mm Hg based upon the average of two or more properly measured readings at each of two or more visits after an initial screen<ref name="pmid12748199">{{cite journal| author=Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL et al.| title=The Seventh Report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. | journal=JAMA | year= 2003 | volume= 289 | issue= 19 | pages= 2560-72 | pmid=12748199 | doi=10.1001/jama.289.19.2560 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=12748199}}</ref>.
The age to begin screening for hypertension varies between 13-20 years of age, according to different authorities. Generally, hypertension is defined as SBP > 140 mmHg and/or DBP > 90 mmHg. In specific populations, however, routine follow-up target BP may be different; and initiation of treatment may be considered at even lower BP values than those considered for the normal population.


==Natural History, Complications, Prognosis==
==Natural History, Complications and Prognosis==
Even moderate elevation of arterial blood pressure leads to shortened life expectancy. At severely high pressures, mean arterial pressures 50% or more above average, a person can expect to live no more than just a few years unless appropriately treated.<ref>Textbook of Medical Physiology, 7th Ed., Guyton & Hall, Elsevier-Saunders, ISBN 0-7216-0240-1, page 220.</ref>
Hypertension is a well-established risk factor for several serious diseases. Chronic uncontrolled hypertension can be complicated by target organ damage. Most common damaged organs include the cardiovascular system, the brain, the kidneys, and the retina. Even moderate elevation of arterial blood pressure leads to a shortened life expectancy. The risk of cardiovascular complications is significantly increased even with small incremental increases in blood pressures. Blood pressure values should never be regarded as distinct stages or grades, but rather as a continuum of risk. Ultimately, hypertension should never be evaluated in isolation as a cardiovascular risk; it should always be integrated with other risk factors for the decision of optimal management and how aggressive the lowering of blood pressure values must reach.


==Diagnosis==
==Diagnosis==
===History and Symptoms===
===History===
Hypertension is usually found incidentally  by healthcare professionals during a routine checkup. The only test for hypertension is a blood pressure measurement.
Thorough history-taking is crucial for the diagnosis and assessment of hypertension. Not only should history-taking be targeted to identify symptoms consistent with high blood pressure, but more importantly it should address risk factors and target organ damage. History-taking alone may be sufficient to diagnose some causes of secondary hypertension, such as drug-induced hypertension, and may guide healthcare providers towards individualized work-up and tailored management.
 
===Physical Examination===
Physical examination of a patient with isolated hypertension in the absence of target organ damage is usually unimpressive with the exception of high blood pressure. Healthcare providers must nonetheless search thoroughly for findings on physical examination that might suggest target organ damage and associated clinical conditions.
 
===Blood Pressure Measurement===
===Blood Pressure Measurement===
In daily practice, the frequently adopted technique for [[blood pressure]] measurement is the [[sphygmomanometer]]. Devices can be electronic, commonly used for better home blood pressure measurement, aneroid, or mercury, with the latter being the gold standard. Hypertension (HTN) is generally defined as an elevated systolic blood pressure (SBP) ≥ 140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg at each of two or more visits<ref name="pmid16512265">{{cite journal| author=Cuddy ML| title=Treatment of hypertension: guidelines from JNC 7 (the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure 1). | journal=J Pract Nurs | year= 2005 | volume= 55 | issue= 4 | pages= 17-21; quiz 22-3 | pmid=16512265 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16512265  }} </ref>. However, target blood pressure values are set at a lower threshold in specific populations, such as diabetics and subjects with significant proteinuria.
The use of a sphygmomanometer in the clinic to measure blood pressure is the most accurate technique to diagnose hypertension. Blood pressure measurements must be performed appropriately according to a standardized technique that involves adequate device and cuff choice and comfortable positions. Sources of error, involving the sphygmomanometer, the patient, and the technique itself must also be considered and avoided. Other techniques for diagnosis, such as ambulatory and self blood pressure measurements may also be helpful, particularly for the follow-up of patients with hypertension.
 
===Laboratory Findings===
===Laboratory Findings===
Laboratory studies are often undertaken to identify possible causes of [[secondary hypertension]], and seek evidence for end-organ damage to the heart itself or the eyes (retina) and kidneys. Diabetes and raised cholesterol levels being additional risk factors for the development of cardiovascular disease are also tested for as they will also require management.
Laboratory studies are often undertaken to identify possible causes of [[secondary hypertension]], and seek evidence for end-organ damage to the heart itself or the eyes (retina) and kidneys. Diabetes and raised cholesterol levels being additional risk factors for the development of cardiovascular disease are also tested for as they will also require management.
===Electrocardiogram===
===Electrocardiography===
An [[electrocardiogram]] (EKG/ECG) is performed to evaluate for the presence of [[left ventricular hypertrophy]] or [[silent myocardial infarction]].
An [[electrocardiogram]] (EKG/ECG) is performed to evaluate for the presence of [[left ventricular hypertrophy]] or [[silent myocardial infarction]].
===Echocardgiography===
On 2D echocardiography, signs of LVH and heart failure are mostly seen in hypertensive patients.
===Chest X Ray===
===Chest X Ray===
A [[chest X-ray]] is performed to evaluate for signs of [[cardiac enlargement]] ([[cardiomegaly]]) or evidence of [[Congestive heart failure|cardiac failure]].
A [[chest X-ray]] may show signs of congestive heart failure, such as cardiomegaly, pulmonary edema, and Kirley B lines.


==Treatment==
==Treatment==
===Lifestyle Modification==
===Lifestyle Modification===
Hypertension is the most common primary diagnosis in America.<ref name="pmid14656957">{{cite journal| author=Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL et al.| title=Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. | journal=Hypertension | year= 2003 | volume= 42 | issue= 6 | pages= 1206-52 | pmid=14656957 | doi=10.1161/01.HYP.0000107251.49515.c2 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14656957  }} </ref> Initial treatment for hypertension generally involves lifestyle modifications (nonpharmacologic therapy), which is also critical for prevention of the disease. Modifications encouraged for hypertensive patients include moderate dietary salt restriction, maintain body weight or weight reduction in obese patients, increased intake of fruits and vegetables and low-fat dairy products, limited alcohol intake, and regular aerobic exercise. Although effective control of blood pressure can be achieved in most patients with hypertension, the majority will require 2 or more antihypertensive drugs.<ref name="pmid14656957">{{cite journal| author=Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL et al.| title=Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. | journal=Hypertension | year= 2003 | volume= 42 | issue= 6 | pages= 1206-52 | pmid=14656957 | doi=10.1161/01.HYP.0000107251.49515.c2 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14656957  }} </ref>
Hypertension is the most common primary diagnosis in America.<ref name="pmid14656957">{{cite journal| author=Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL et al.| title=Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. | journal=Hypertension | year= 2003 | volume= 42 | issue= 6 | pages= 1206-52 | pmid=14656957 | doi=10.1161/01.HYP.0000107251.49515.c2 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14656957  }} </ref> Initial treatment for hypertension generally involves lifestyle modifications (nonpharmacologic therapy), which is also critical for prevention of the disease. Modifications encouraged for hypertensive patients include moderate dietary salt restriction, maintain body weight or weight reduction in obese patients, increased intake of fruits and vegetables and low-fat dairy products, limited alcohol intake, and regular aerobic exercise. Although effective control of blood pressure can be achieved in most patients with hypertension, the majority will require 2 or more antihypertensive drugs.<ref name="pmid14656957">{{cite journal| author=Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL et al.| title=Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure. | journal=Hypertension | year= 2003 | volume= 42 | issue= 6 | pages= 1206-52 | pmid=14656957 | doi=10.1161/01.HYP.0000107251.49515.c2 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=14656957  }} </ref>
===Medical Therapy===
===Medical Therapy===
There are three main classes of drugs that are used for initial monotherapy (when no specific indication requires other treatment methods): [[thiazide diuretics]], long-acting calcium channel blockers (usually a [[dihydropyridine]]), and [[ACE inhibitors]] or [[angiotensin II receptor blockers]].  In some cases, particularly with patients having moderate to severe hypertension, single agent therapy does not control the blood pressure. Over time, patients who were initially controlled with monotherapy need to increase treatment to a combined therapy in order for continued blood pressure control. The primary determinant of the outcome is the attained blood pressure, not the specific drug(s) used. The goal of antihypertensive therapy in patients with uncomplicated combined systolic and diastolic hypertension is a blood pressure of below 140/90 mmHg.
Medical therapy is considered the most efficient means for the reduction of both systolic and diastolic blood pressure values in patients with hypertension. The two most important approaches for pharmacologic therapy in hypertension are proposed by JNC-7 guidelines in 2004 and more recently by the ESH/ESC guidelines in 2013. With the emergence of recent data, a major shift from the classical use of thiazide-type diuretics as first line therapy for patients with isolated essential hypertension has occurred. Recent guidelines currently encourage the use of any anti-hypertensive agent for isolated essential hypertension. Nonetheless, various conditions warrant the use of specific classes that have been found to have compelling indications in certain diseases and among specific patient populations.
===Cost-Effectiveness of Therapy===
In the [[ALLHAT trial]], [[thiazide]] diuretics were just as effective as [[ACE inhibitors]] and [[calcium channel blockers]] and for this reason they are often used as first line therapy for hypertension.


==References==
==References==

Latest revision as of 14:00, 17 May 2017

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Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Assistant Editor-In-Chief: Yazan Daaboul, Serge Korjian, Taylor Palmieri

Overview

Arterial blood pressure (BP) is a measure of the force exerted by the blood on the arterial walls. It is the function of both the cardiac output (CO) and the systemic vascular resistance (SVR). The maintenance of a normal blood pressure value is crucial to ensure appropriate blood circulation throughout the cardiovascular system. Arterial BP is considered one of the most important vital signs in the clinical setting.

Hypertension (HTN) is generally defined as an elevated systolic blood pressure (SBP) ≥ 140 mmHg and/or diastolic blood pressure (DBP) ≥ 90 mmHg at each of two or more visits.[1] However, target BP values are set at a lower threshold in specific populations, such as diabetics and subjects with significant proteinuria and other renal diseases.

Classification

In 2004, the Seventh Report of the Joint National Committee (JNC 7) classified blood pressure values into 4 categories: normal, prehypertension, stage I hypertension, and stage II hypertension.[1] In 2007, the Task Force for the Management of Arterial Hypertension of the European Society of Hypertension (ESH) and the European Society of Cardiology (ESC) classified blood pressure into 7 categories.[2] This classification remained unchanged in the 2013 ESH/ESC classification.[3] The ESH/ESC classification excludes JNC 7’s pre-hypertension category, but includes 3 different grades of hypertension in contrast to JNC 7’s two-stage classification of hypertension.

Pathophysiology

Although the pathophysiology of secondary hypertension has been outlined, there is still much debate about the true pathogenesis of primary (essential) hypertension. It is now conceded that hypertension is caused by multiple genetic and environmental factors with varying roles between individuals.[1]

Causes

The prevalence of primary hypertension is much more common than secondary hypertension, where only 5-10% of hypertension cases are diagnosed as secondary hypertension[4]. When a full evaluation yields no clear etiology for the hypertension, the latter is thus identified as primary or essential hypertension. It is considered a chronic disease that requires lifetime treatment and management. If an underlying disease is identifiable as the cause of hypertension, the latter is called secondary hypertension. Causes of secondary hypertension include obstructive sleep apnea, hyperaldosteronism, kidney diseases, excess catecholamines, coarctation, cushing syndrome among other diseases.

 
 
Chronic hypertension
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Primary hypertension
(also known as essential hypertension)
(95% of the cases)
 
Secondary hypertension

(5% of the cases)

Differentiating Hypertension from other Diseases

Before the diagnosis of primary (essential) hypertension, secondary causes of hypertension should be ruled out. Additionally, other conditions that may elevate BP include: White coat hypertension, masked hypertension, and pseudohypertension.

Epidemiology and Demographics

Hypertension is considered an epidemic worldwide. It continues to be one of the most common diseases. In October 2013, CDC data from the 2011-2012 National Health And Nutrition Examination Survey (NHANES) demonstrated that the overall age-adjusted prevalence of hypertension among U.S. adults aged 18 and older was 29.1%.[5] Similar surveys conducted in Europe estimated the prevalence of hypertension to be 44%.[6] The prevalence of hypertension increases among older patients and among non-Hispanic black patients, but is similar in both genders.

Risk Factors

Established risk factors for essential hypertension include old age, male gender, African American ethnicity, dyslipidemia, diabetes mellitus, smoking, increased salt intake in diet, obesity, and sedentary lifestyle. Studies are currently assessing the role of new emerging factors that might be considered as new risk factors for the development of hypertension.

Screening

The age to begin screening for hypertension varies between 13-20 years of age, according to different authorities. Generally, hypertension is defined as SBP > 140 mmHg and/or DBP > 90 mmHg. In specific populations, however, routine follow-up target BP may be different; and initiation of treatment may be considered at even lower BP values than those considered for the normal population.

Natural History, Complications and Prognosis

Hypertension is a well-established risk factor for several serious diseases. Chronic uncontrolled hypertension can be complicated by target organ damage. Most common damaged organs include the cardiovascular system, the brain, the kidneys, and the retina. Even moderate elevation of arterial blood pressure leads to a shortened life expectancy. The risk of cardiovascular complications is significantly increased even with small incremental increases in blood pressures. Blood pressure values should never be regarded as distinct stages or grades, but rather as a continuum of risk. Ultimately, hypertension should never be evaluated in isolation as a cardiovascular risk; it should always be integrated with other risk factors for the decision of optimal management and how aggressive the lowering of blood pressure values must reach.

Diagnosis

History

Thorough history-taking is crucial for the diagnosis and assessment of hypertension. Not only should history-taking be targeted to identify symptoms consistent with high blood pressure, but more importantly it should address risk factors and target organ damage. History-taking alone may be sufficient to diagnose some causes of secondary hypertension, such as drug-induced hypertension, and may guide healthcare providers towards individualized work-up and tailored management.

Physical Examination

Physical examination of a patient with isolated hypertension in the absence of target organ damage is usually unimpressive with the exception of high blood pressure. Healthcare providers must nonetheless search thoroughly for findings on physical examination that might suggest target organ damage and associated clinical conditions.

Blood Pressure Measurement

The use of a sphygmomanometer in the clinic to measure blood pressure is the most accurate technique to diagnose hypertension. Blood pressure measurements must be performed appropriately according to a standardized technique that involves adequate device and cuff choice and comfortable positions. Sources of error, involving the sphygmomanometer, the patient, and the technique itself must also be considered and avoided. Other techniques for diagnosis, such as ambulatory and self blood pressure measurements may also be helpful, particularly for the follow-up of patients with hypertension.

Laboratory Findings

Laboratory studies are often undertaken to identify possible causes of secondary hypertension, and seek evidence for end-organ damage to the heart itself or the eyes (retina) and kidneys. Diabetes and raised cholesterol levels being additional risk factors for the development of cardiovascular disease are also tested for as they will also require management.

Electrocardiography

An electrocardiogram (EKG/ECG) is performed to evaluate for the presence of left ventricular hypertrophy or silent myocardial infarction.

Echocardgiography

On 2D echocardiography, signs of LVH and heart failure are mostly seen in hypertensive patients.

Chest X Ray

A chest X-ray may show signs of congestive heart failure, such as cardiomegaly, pulmonary edema, and Kirley B lines.

Treatment

Lifestyle Modification

Hypertension is the most common primary diagnosis in America.[7] Initial treatment for hypertension generally involves lifestyle modifications (nonpharmacologic therapy), which is also critical for prevention of the disease. Modifications encouraged for hypertensive patients include moderate dietary salt restriction, maintain body weight or weight reduction in obese patients, increased intake of fruits and vegetables and low-fat dairy products, limited alcohol intake, and regular aerobic exercise. Although effective control of blood pressure can be achieved in most patients with hypertension, the majority will require 2 or more antihypertensive drugs.[7]

Medical Therapy

Medical therapy is considered the most efficient means for the reduction of both systolic and diastolic blood pressure values in patients with hypertension. The two most important approaches for pharmacologic therapy in hypertension are proposed by JNC-7 guidelines in 2004 and more recently by the ESH/ESC guidelines in 2013. With the emergence of recent data, a major shift from the classical use of thiazide-type diuretics as first line therapy for patients with isolated essential hypertension has occurred. Recent guidelines currently encourage the use of any anti-hypertensive agent for isolated essential hypertension. Nonetheless, various conditions warrant the use of specific classes that have been found to have compelling indications in certain diseases and among specific patient populations.

References

  1. 1.0 1.1 1.2 Cuddy ML (2005). "Treatment of hypertension: guidelines from JNC 7 (the seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure 1)". J Pract Nurs. 55 (4): 17–21, quiz 22-3. PMID 16512265.
  2. Bonny A, Lacombe F, Yitemben M, Discazeaux B, Donetti J, Fahri P; et al. (2008). "The 2007 ESH/ESC guidelines for the management of arterial hypertension". J Hypertens. 26 (4): 825, author reply 825-6. doi:10.1097/HJH.0b013e3282f857e7. PMID 18327095.
  3. Mancia G, Fagard R, Narkiewicz K, Redón J, Zanchetti A, Böhm M; et al. (2013). "2013 ESH/ESC Guidelines for the management of arterial hypertension: the Task Force for the management of arterial hypertension of the European Society of Hypertension (ESH) and of the European Society of Cardiology (ESC)". J Hypertens. 31 (7): 1281–357. doi:10.1097/01.hjh.0000431740.32696.cc. PMID 23817082.
  4. Onusko E (2003). "Diagnosing secondary hypertension". Am Fam Physician. 67 (1): 67–74. PMID 12537168.
  5. Nwankwo T, Yoon SS, Burt V, Gu Q (2013). "Hypertension among adults in the United States: national health and nutrition examination survey, 2011-2012". NCHS Data Brief (133): 1–8. PMID 24171916.
  6. Wolf-Maier K, Cooper RS, Banegas JR, Giampaoli S, Hense HW, Joffres M; et al. (2003). "Hypertension prevalence and blood pressure levels in 6 European countries, Canada, and the United States". JAMA. 289 (18): 2363–9. doi:10.1001/jama.289.18.2363. PMID 12746359.
  7. 7.0 7.1 Chobanian AV, Bakris GL, Black HR, Cushman WC, Green LA, Izzo JL; et al. (2003). "Seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure". Hypertension. 42 (6): 1206–52. doi:10.1161/01.HYP.0000107251.49515.c2. PMID 14656957.

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