Assessment of hypertension

Hypertension is a common disorder that affects a large proportion of the community. It is usually asymptomatic and is detected on routine examination or after the occurrence of a complication such as a heart attack or stroke.[1]Lip GY. Hypertension, platelets, and the endothelium: the "thrombotic paradox" of hypertension (or "Birmingham paradox") revisited. Hypertension. 2003 Feb;41(2):199-200. http://hyper.ahajournals.org/cgi/content/full/41/2/199 http://www.ncbi.nlm.nih.gov/pubmed/12574081?tool=bestpractice.com

The 2017 ACC/AHA guidelines for the prevention, detection, evaluation, and management of high blood pressure in adults defines hypertension as any systolic blood pressure measurement of ≥130 mmHg or any diastolic blood pressure measurement of ≥80 mmHg.[2]Whelton PK, Carey RM, Aronow WS, et al. 2017 ACC/AHA/AAPA/ABC/ACPM/AGS/APhA/ASH/ASPC/NMA/PCNA guideline for the prevention, detection, evaluation, and management of high blood pressure in adults. J Am Coll Cardiol. 2018 May 15;71(19):e127-248. http://www.ncbi.nlm.nih.gov/pubmed/29146535?tool=bestpractice.com ACC/AHA blood pressure categories are defined as follows:

• Elevated blood pressure: systolic blood pressure of 120-129 mmHg and diastolic blood pressure of <80 mmHg

• Stage 1 hypertension: systolic blood pressure of 130-139 mmHg and/or diastolic blood pressure of 80-89 mmHg

• Stage 2 hypertension: systolic blood pressure of ≥140 mmHg and/or diastolic blood pressure of ≥90 mmHg.

The 2017 ACC/AHA guidelines definition represents a more aggressive approach to diagnosis and treatment of hypertension compared with Joint National Committee (JNC) 7 and JNC 8 recommendations, where blood pressure in the range of 120-139 mmHg/80-89 mmHg is considered pre-hypertension and blood pressure >140/90 mmHg is considered elevated.[3]Chobanian AV, Bakris GL, Black HR, et al. The seventh report of the Joint National Committee on Prevention, Detection, Evaluation, and Treatment of High Blood Pressure: the JNC 7 report. JAMA. 2003 May 21;289(19):2560-72. http://www.ncbi.nlm.nih.gov/pubmed/12748199?tool=bestpractice.com [4]James PA, Oparil S, Carter BL, et al. 2014 evidence-based guideline for the management of high blood pressure in adults: report from the panel members appointed to the Eighth Joint National Committee (JNC 8). JAMA. 2014 Feb 5;311(5):507-20. http://jama.jamanetwork.com/article.aspx?articleid=1791497 http://www.ncbi.nlm.nih.gov/pubmed/24352797?tool=bestpractice.com

Publication of the 2017 ACC/AHA guidelines has prompted widespread debate, and there are calls for the recommendations to be revisited. Implementing the guidelines would increase the prevalence of hypertension by 26.8% in the US. Critics are concerned that labelling more patients as hypertensive could increase psychological morbidity, as well as exposing lower-risk patients to the potential harm of antihypertensive medications.[5]Khera R, Lu Y, Lu J, et al. Impact of 2017 ACC/AHA guidelines on prevalence of hypertension and eligibility for antihypertensive treatment in United States and China: nationally representative cross sectional study. BMJ. 2018 Jul 11;362:k2357. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6039831 http://www.ncbi.nlm.nih.gov/pubmed/29997129?tool=bestpractice.com

The 2017 ACC/AHA guidelines were mainly based on the results of the SPRINT trial, which investigated intensive or standard hypertension treatment in people with a systolic blood pressure of ≥130 mmHg with an increased cardiovascular risk (but without diabetes).[6]SPRINT Research Group; Wright JT Jr, Williamson JD, Whelton PK, et al. A randomized trial of intensive versus standard blood-pressure control. N Engl J Med. 2015 Nov 26;373(22):2103-16. https://www.nejm.org/doi/10.1056/NEJMoa1511939 http://www.ncbi.nlm.nih.gov/pubmed/26551272?tool=bestpractice.com Listen to our podcast for more on the controversy. BMJ Best Practice Podcast: hypertension Opens in new window

European guideline blood pressure categories are defined as follows:[7]McEvoy JW, McCarthy CP, Bruno RM, et al. 2024 ESC guidelines for the management of elevated blood pressure and hypertension. Eur Heart J. 2024 Oct 7;45(38):3912-4018. https://academic.oup.com/eurheartj/article/45/38/3912/7741010

• Elevated blood pressure: office systolic blood pressure 120-139 mmHg or office diastolic blood pressure 70-89 mmHg

• Hypertension: office systolic blood pressure ≥140 mmHg or office diastolic blood pressure ≥90 mmHg.

For the diagnosis of elevated blood pressure or hypertension to be made, the European guidelines recommend confirmation with out-of-office measurements or at least one repeat office measurement at a subsequent visit.[7]McEvoy JW, McCarthy CP, Bruno RM, et al. 2024 ESC guidelines for the management of elevated blood pressure and hypertension. Eur Heart J. 2024 Oct 7;45(38):3912-4018. https://academic.oup.com/eurheartj/article/45/38/3912/7741010 ​ Isolated systolic hypertension is defined as a systolic blood pressure ≥140 mmHg, with a diastolic blood pressure <90 mmHg.[7]McEvoy JW, McCarthy CP, Bruno RM, et al. 2024 ESC guidelines for the management of elevated blood pressure and hypertension. Eur Heart J. 2024 Oct 7;45(38):3912-4018. https://academic.oup.com/eurheartj/article/45/38/3912/7741010

The UK National Institute for Health and Care Excellence states that a diagnosis of hypertension is confirmed in those with:[8]National Institute for Health and Care Excellence. Hypertension in adults: diagnosis and management. Nov 2023 [internet publication]. https://www.nice.org.uk/guidance/ng136

• a clinic blood pressure of ≥140/90 mmHg, and

• daytime ambulatory blood pressure monitoring average or home blood pressure monitoring average of ≥135/85 mmHg.

Although different studies have used a variety of cut-off points for the diagnosis of hypertension in the community, any blood pressure >120 mmHg systolic is associated with an increased cardiovascular risk. The importance of hypertension is its relation to other cardiovascular risk factors and consequent overall cardiovascular risk.

The AHA defines resistant hypertension as:[9]Carey RM, Calhoun DA, Bakris GL, et al. Resistant hypertension: detection, evaluation, and management: a scientific statement from the American Heart Association. Hypertension. 2018 Nov;72(5):e53-90. https://www.ahajournals.org/doi/full/10.1161/HYP.0000000000000084 http://www.ncbi.nlm.nih.gov/pubmed/30354828?tool=bestpractice.com

• Clinic blood pressure >130/80 mmHg despite the concurrent use of at least 3 antihypertensive agents (including an ACE inhibitor or angiotensin receptor antagonist, a long-acting calcium channel blocker, and a diuretic) at maximum or maximally tolerated doses.

• Patients who require 4 or more antihypertensive agents to achieve their target blood pressure are also considered to have resistant hypertension. The diagnosis requires the exclusion of white-coat hypertension and poor adherence with antihypertensive medication.

This topic addresses the assessment of hypertension in adults.

Epidemiology

According to a global analysis of trends in hypertension, the number of adults aged 30-79 years with hypertension increased from 650 million to 1.28 billion in the period 1990-2019.[10]NCD Risk Factor Collaboration (NCD-RisC). Worldwide trends in hypertension prevalence and progress in treatment and control from 1990 to 2019: a pooled analysis of 1201 population-representative studies with 104 million participants. Lancet. 2021 Sep 11;398(10304):957-80. https://www.thelancet.com/journals/lancet/article/PIIS0140-6736(21)01330-1/fulltext http://www.ncbi.nlm.nih.gov/pubmed/34450083?tool=bestpractice.com ​ Based on National Health and Nutrition Survey (NHANES) data from 2017-2020, an estimated 122.4 million US adults aged ≥20 years have hypertension (defined as self-reported use of antihypertensive medicine, systolic BP ≥130 mmHg or diastolic BP ≥80 mmHg).[11]Martin SS, Aday AW, Almarzooq ZI, et al. 2024 heart disease and stroke statistics: a report of US and global data from the American Heart Association. 2024 Feb 20;149(8):e347-913. https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000001209 http://www.ncbi.nlm.nih.gov/pubmed/38264914?tool=bestpractice.com  During this period, the prevalence of hypertension was 28.5% among those aged 20-44 years, 58.6% among those aged 45-64 years, and 76.5% among those aged ≥65 years.[11]Martin SS, Aday AW, Almarzooq ZI, et al. 2024 heart disease and stroke statistics: a report of US and global data from the American Heart Association. 2024 Feb 20;149(8):e347-913. https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000001209 http://www.ncbi.nlm.nih.gov/pubmed/38264914?tool=bestpractice.com  The prevalence may be similar or higher in Western Europe.[12]Falaschetti E, Mindell J, Knott C, et al. Hypertension management in England: a serial cross-sectional study from 1994 to 2011. Lancet. 2014 May 31;383(9932):1912-9. http://www.ncbi.nlm.nih.gov/pubmed/24881995?tool=bestpractice.com [13]Lacruz ME, Kluttig A, Hartwig S, et al. Prevalence and incidence of hypertension in the general adult population: results of the CARLA-cohort study. Medicine (Baltimore). 2015 Jun;94(22):e952. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4616348 http://www.ncbi.nlm.nih.gov/pubmed/26039136?tool=bestpractice.com

In 2010, the estimated global age-standardised prevalence of hypertension in adults aged ≥20 years was 31.1%; 28.5% in high-income countries and 31.5% in low- and middle-income countries.[14]Mills KT, Bundy JD, Kelly TN, et al. Global disparities of hypertension prevalence and control: a systematic analysis of population-based studies from 90 countries. Circulation. 2016 Aug 9;134(6):441-50. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4979614 http://www.ncbi.nlm.nih.gov/pubmed/27502908?tool=bestpractice.com

Prevalence by sex has been found to differ with age with prevalence higher in men than in women aged <65 years, but higher in women than in men aged ≥65 years.[11]Martin SS, Aday AW, Almarzooq ZI, et al. 2024 heart disease and stroke statistics: a report of US and global data from the American Heart Association. 2024 Feb 20;149(8):e347-913. https://www.ahajournals.org/doi/full/10.1161/CIR.0000000000001209 http://www.ncbi.nlm.nih.gov/pubmed/38264914?tool=bestpractice.com [14]Mills KT, Bundy JD, Kelly TN, et al. Global disparities of hypertension prevalence and control: a systematic analysis of population-based studies from 90 countries. Circulation. 2016 Aug 9;134(6):441-50. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4979614 http://www.ncbi.nlm.nih.gov/pubmed/27502908?tool=bestpractice.com

Hypertension is more prevalent in black people than in white people, starting in childhood, with 76% of black men and women developing hypertension by age 55 years, compared with 55% and 40% of white men and women, respectively.[15]Thomas SJ, Booth JN 3rd, Dai C, et al. Cumulative incidence of hypertension by 55 years of age in blacks and whites: the CARDIA study. J Am Heart Assoc. 2018 Jul 11;7(14). https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6064834 http://www.ncbi.nlm.nih.gov/pubmed/29997132?tool=bestpractice.com

The exact prevalence of hypertension is difficult to assess, as it is usually asymptomatic. Prevalence is expected to rise as the 'cut-off' value for hypertension is re-defined at a lower level.

Approximately 15% of patients with hypertension have resistant hypertension.[9]Carey RM, Calhoun DA, Bakris GL, et al. Resistant hypertension: detection, evaluation, and management: a scientific statement from the American Heart Association. Hypertension. 2018 Nov;72(5):e53-90. https://www.ahajournals.org/doi/full/10.1161/HYP.0000000000000084 http://www.ncbi.nlm.nih.gov/pubmed/30354828?tool=bestpractice.com

Complications and hypertension-mediated organ damage

Studies have shown that treatment of hypertension can reduce the incidence of future cardiovascular and cerebrovascular events.[16]Ogden LG, He J, Lydick E, et al. Long-term absolute benefit of lowering blood pressure in hypertensive patients according to the JNC VI risk stratification. Hypertension. 2000 Feb;35(2):539-43. http://hyper.ahajournals.org/cgi/content/full/35/2/539 http://www.ncbi.nlm.nih.gov/pubmed/10679494?tool=bestpractice.com [17]D'Anci KE, Tipton K, Hedden-Gross A, et al. Effect of intensive blood pressure lowering on cardiovascular outcomes: a systematic review prepared for the 2020 U.S. Department of Veterans Affairs/U.S. Department of Defense Guidelines. Ann Intern Med. 2020 Dec 1;173(11):895-903. http://www.ncbi.nlm.nih.gov/pubmed/32866419?tool=bestpractice.com ​ The aim of early diagnosis and treatment of hypertension is to lower overall cardiovascular risk and prevent cerebrovascular events.

The effects of chronic hypertension on organ systems are referred to as hypertension-mediated organ damage.

Left ventricular hypertrophy, cardiovascular disease, cerebrovascular disease, hypertensive retinopathy, and nephropathy are the most common manifestations.[18]Nadar SK, Tayebjee MH, Meserelli F, et al. Target organ damage in hypertension: pathophysiology and implications for drug therapy. Curr Pharm Des. 2006;12(13):1581-92. http://www.ncbi.nlm.nih.gov/pubmed/16729871?tool=bestpractice.com The presence of left ventricular hypertrophy is a poor prognostic sign, and regression of left ventricular hypertrophy improves prognosis.[19]Lewington S, Clarke R, Qizilbash N, et al. Age-specific relevance of usual blood pressure to vascular mortality: a meta-analysis of individual data for one million adults in 61 prospective studies. Lancet. 2002 Dec 14;360(9349):1903-13. http://www.ncbi.nlm.nih.gov/pubmed/12493255?tool=bestpractice.com Patients with resistant hypertension are at higher risk of experiencing cardiovascular and cerebrovascular events and developing chronic kidney disease.[9]Carey RM, Calhoun DA, Bakris GL, et al. Resistant hypertension: detection, evaluation, and management: a scientific statement from the American Heart Association. Hypertension. 2018 Nov;72(5):e53-90. https://www.ahajournals.org/doi/full/10.1161/HYP.0000000000000084 http://www.ncbi.nlm.nih.gov/pubmed/30354828?tool=bestpractice.com

Cardiovascular risk

Guidelines on the management of hypertension emphasise the importance of calculating and managing the overall cardiovascular risk of a patient, rather than focusing only on blood pressure readings. The ACC and AHA have published an online tool to calculate patients’ 10-year and lifetime risk of atherosclerotic cardiovascular disease. ACC: ASCVD Risk Estimator Plus Opens in new window

For individuals aged 40-70 years, each increment of 20 mmHg in systolic blood pressure or 10 mmHg in diastolic blood pressure across the entire blood pressure range from 115/75 to 185/115 mmHg doubles the risk of cardiovascular disease.[20]Blair SN, Goodyear NN, Gibbons LW, et al. Physical fitness and incidence of hypertension in healthy normotensive men and women. JAMA. 1984 Jul 27;252(4):487-90. http://www.ncbi.nlm.nih.gov/pubmed/6737638?tool=bestpractice.com The European Society for Cardiology has proposed that sex-specific thresholds may be appropriate as lower blood pressure levels are associated with an increased risk of cardiovascular disease in women.[21]Gerdts E, Sudano I, Brouwers S, et al. Sex differences in arterial hypertension. Eur Heart J. 2022 Dec 7;43(46):4777-88. https://academic.oup.com/eurheartj/article/43/46/4777/6711154?login=false http://www.ncbi.nlm.nih.gov/pubmed/36136303?tool=bestpractice.com ​ Treating associated cardiovascular risk factors such as obesity, diabetes, hypercholesterolaemia, and smoking are as important as managing hypertension in lowering overall cardiovascular risk.