What Is Hypertension?

Hypertension is a chronic cardiovascular condition defined by sustained elevation of arterial blood pressure above thresholds associated with increased risk of organ damage and cardiovascular events. Blood pressure is expressed as two values in millimeters of mercury (mmHg): the systolic pressure, which reflects peak arterial pressure during ventricular contraction, and the diastolic pressure, which represents the lowest arterial pressure during ventricular relaxation. Guidelines from the American College of Cardiology and the American Heart Association define hypertension as a systolic reading at or above 130 mmHg or a diastolic reading at or above 80 mmHg, a threshold revised downward in 2017 from the previous 140/90 mmHg standard.

The condition draws on contributions from physiology, vascular biology, pharmacology, and biomedical engineering. Underlying mechanisms include overactivity of the renin-angiotensin-aldosterone system, increased sympathetic nervous system tone, impaired renal pressure regulation, and endothelial dysfunction. Primary hypertension, which accounts for approximately 90 percent of cases, has no single identifiable cause; secondary hypertension arises from specific conditions such as renal artery stenosis or primary aldosteronism.

Measurement and Diagnosis

Accurate blood pressure measurement is the foundation of hypertension diagnosis. The auscultatory method uses an inflatable cuff and a sphygmomanometer to identify Korotkoff sounds, the characteristic tapping that marks the onset and disappearance of audible arterial pulsation. As described in the NCBI StatPearls reference on blood pressure measurement, automated oscillometric devices analyze oscillations in arterial wall motion as the cuff deflates, allowing unsupervised office measurements that reduce the white-coat effect. Ambulatory blood pressure monitoring records readings over 24 hours and is considered particularly useful for identifying masked hypertension, a pattern in which clinic readings appear normal while average daytime pressures are elevated.

Wearable and Cuffless Monitoring

Conventional cuff-based measurement captures only isolated snapshots of blood pressure. Biomedical engineering research has pursued continuous, cuffless devices capable of tracking pressure throughout daily activity. Technologies under investigation include photoplethysmographic (PPG) sensors that estimate blood pressure from pulse wave transit time, tonometric sensors that apply calibrated pressure over a superficial artery, and ultrasonic transducer arrays that directly image vessel wall dynamics. A systematic review published in PMC covering wearable blood pressure monitoring devices found that wearable monitors using mechanoelectric, optoelectronic, and electrophysiological sensing mechanisms show promise for enabling dense longitudinal data collection, though clinical-grade accuracy across varied postures and activity levels remains an active research challenge.

Pharmacological and Non-Pharmacological Management

Treatment follows a stepwise approach combining lifestyle modification with antihypertensive drug therapy when lifestyle changes alone are insufficient. Lifestyle interventions with demonstrated efficacy include sodium restriction below 2.3 grams per day, aerobic exercise, the Dietary Approaches to Stop Hypertension (DASH) dietary pattern, moderation of alcohol consumption, and weight reduction. Pharmacological management draws primarily from five drug classes: angiotensin-converting enzyme inhibitors, angiotensin receptor blockers, calcium channel blockers, thiazide diuretics, and beta-blockers. Research surveyed in the AHA journal Management of Hypertension in the Digital Era examines how digital health platforms, including telemedicine and remote monitoring, improve medication adherence and hypertension control rates at a population level.

Applications

Hypertension research and management has applications in a wide range of disciplines, including:

• Wearable health monitoring devices for continuous cardiovascular surveillance
• Clinical decision support systems integrating ambulatory blood pressure data
• Telehealth platforms for remote patient management
• Population-level epidemiological modeling for cardiovascular risk
• Drug delivery systems targeting renin-angiotensin pathway regulation