Hypertension in Adults: An Update

This is a summarized version of the full in-depth article on Relias Media.

AUTHORS

Alfred C. Gitu, MD, FAAFP, Program Director and Associate Professor of Family Medicine, The Florida State University COM Family Medicine Residency Program at Lee Health, Fort Myers, FL

Hailon Wong, MD, Assistant Professor of Family Medicine, The Florida State University COM Family Medicine Residency Program at Lee Health, Fort Myers, FL

PEER REVIEWER

Harvey S. Hahn, MD, FACC, Cardiovascular Fellowship Training Program and Co-Director, KPN CV Quality, Kettering Medical Center; Associate Professor of Clinical Medicine, Wright State University Boonshoft School of Medicine, Kettering, OH, and Loma Linda, CA

Definition of Hypertension

Hypertension is a common condition characterized by persistently elevated blood pressure (BP). Most major international guidelines, such as those from the European Society of Cardiology/European Society of Hypertension (ESC/ESH) and the International Society of Hypertension (ISH), define hypertension as systolic blood pressure (SBP) ≥ 140 mmHg or diastolic blood pressure (DBP) ≥ 90 mmHg based on office measurements.

In contrast, the 2017 American College of Cardiology/American Heart Association (ACC/AHA) guidelines define Stage 1 hypertension as SBP of 130 mmHg to 139 mmHg or DBP of 80 mmHg to 89 mmHg, while Stage 2 hypertension is ≥ 140/90 mmHg . The ACC/AHA guidelines are based largely on the SPRINT trial, which demonstrated that targeting SBP < 120 mmHg improved overall cardiovascular outcomes. These definitions differ from earlier recommendations, such as those from the Eighth Joint National Committee (JNC 8), which defines hypertension as ≥ 140/90 mmHg for adults aged 18-59 years and ≥ 150/90 mmHg for those older than 60 years of age.

Newer guidelines have also adapted blood pressure thresholds based on different settings and measurement techniques, such as home monitoring or 24-hour ambulatory BP monitoring (ABPM). For instance, the ACC/AHA suggests a cutoff of 125/75 mmHg for 24-hour ABPM.

Epidemiology

Hypertension is highly prevalent worldwide, particularly in low- and middle-income countries where access to healthcare and medications is limited. In the United States, hypertension affects more than 45% of adults based on the ACC/AHA’s 130/80 mmHg threshold. Prevalence increases with age, affecting 22.4% of adults aged 18-39 years but rising to 74.5% in those over 60 years of age. Additionally, non-Hispanic Black adults have the highest prevalence (57.1%) compared to other ethnic groups. Even when using the 140/90 mmHg definition, lifetime risk for developing hypertension is more than 90% for African American adults by age 45 years.

Hypertension is the leading cause of death globally, responsible for more than 10 million deaths annually. It significantly increases the risk for cardiovascular disease (CVD), with each 20 mmHg increase in SBP doubling the risk of fatal events like stroke or myocardial infarction.

Etiology and Risk Factors

Hypertension can be classified into two categories: primary hypertension (90% to 95% of cases) and secondary hypertension. Primary hypertension is influenced by multiple factors, including genetics, age, race, obesity, and lifestyle choices like high sodium intake and physical inactivity. Secondary hypertension is caused by conditions such as renal disease, obstructive sleep apnea, hyperaldosteronism, or medications. It is more common in patients with severe hypertension, those younger than 30 years of age, or those with an acute rise in BP after a period of good control.

Pathophysiology

Hypertension is often the result of a complex interaction of genetic, environmental, neural, hormonal, and structural factors. The "mosaic model" describes the interplay between these elements, where lifestyle factors like stress and dietary habits contribute to vascular remodeling and increased vascular resistance. A typical Western diet, high in processed foods, fats, and salt, promotes inflammation and atherosclerosis, further exacerbating hypertension.

Clinical Features

Hypertension is generally asymptomatic, often diagnosed during routine clinical assessments. In severe cases, hypertension can present with complications such as heart failure, chronic kidney disease, and increased risk of stroke and myocardial infarction. Hypertensive emergencies, defined by BP > 180/110 mmHg with end-organ damage, may present with symptoms like headache, chest pain, visual changes, or shortness of breath.

Diagnostic Studies

Accurate BP measurement is critical in diagnosing hypertension. The ACC/AHA recommends obtaining BP readings across multiple visits and settings, such as using home-based or ambulatory BP monitoring to confirm office readings. 

Management

Lifestyle Modifications

Lifestyle changes are the cornerstone of hypertension management, and they can significantly reduce BP. Interventions include:

• A healthy diet, such as the DASH diet, can reduce SBP by up to 11 mmHg.

• Reduced sodium intake, regular physical activity, and weight loss are also critical in lowering BP.

Pharmacologic Treatment

Pharmacotherapy is recommended when lifestyle modifications are insufficient, particularly in patients with high cardiovascular risk or BP > 160/100 mmHg. First-line antihypertensive drugs include thiazide diuretics, angiotensin-converting enzyming (ACE) inhibitors, angiotensin receptor blockers (ARBs), and calcium channel blockers (CCBs). Combination therapy is often necessary to achieve BP control, with the ESC/ESH recommending dual therapy from the start for most patients.

The ACC/AHA advises using specific antihypertensive classes in certain populations. For instance, Black adults are recommended to start with a thiazide diuretic or CCB unless there are compelling indications for other agents. Resistant hypertension, defined as uncontrolled BP on three medications, often requires further evaluation for secondary causes or adherence issues and may benefit from the addition of spironolactone.

Special Populations

• Pregnancy: Methyldopa, nifedipine, or labetalol are preferred treatments. ACE inhibitors and ARBs are contraindicated due to teratogenic risks.

• Temperature Variability: BP levels fluctuate with seasonal changes and can affect control in hypertensive patients, necessitating adjustments.

Summary

Hypertension is a prevalent, modifiable risk factor for cardiovascular disease, and its management requires a comprehensive approach. Lifestyle modifications are critical, but most patients will require pharmacotherapy to achieve BP control. Regular monitoring, including out-of-office measurements, is essential to ensure effective management. A multidisciplinary approach involving healthcare providers, technology, and patient education can further enhance adherence and treatment outcomes.

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We discuss hypertension in adults in more detail and include detailed charts and tables in our full write-up on Relias Media.

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