Blood Pressure

The pressure exerted on blood vessel walls when the heart pumps blood into the vessels; measured as systolic and diastolic blood pressure, with hypertension and hypotension being key indicators of maj

Blood Pressure

Overview

Blood pressure (血壓, Blood Pressure) is the pressure exerted on blood vessel walls when the heart contracts and pumps blood into the arteries. It is generally measured in millimeters of mercury (mmHg) and is expressed as two values: systolic blood pressure, the peak pressure when the heart contracts, and diastolic blood pressure, the lowest pressure when the heart relaxes. Blood pressure is the most basic and important vital indicator for assessing cardiovascular health, and persistent hypertension or hypotension can cause various complications, including stroke, myocardial infarction, and kidney disease.

Main Content

Definition and Physiology of Blood Pressure

Blood pressure is determined by cardiac output (the volume of blood the heart pumps per minute) and peripheral vascular resistance. When the heart contracts, the pressure within the arteries reaches its peak, called systolic blood pressure; while the heart relaxes and refills with blood, pressure is maintained by the elasticity of the arterial walls, called diastolic blood pressure. In healthy adults, it is typically measured at around 120/80 mmHg, and it fluctuates frequently according to age, sex, posture, time of day, and emotional state.

Blood Pressure Measurement Methods

The most common method is office blood pressure measurement, in which a cuff is wrapped around the brachial artery. In addition, ambulatory blood pressure monitoring (ABPM), which records blood pressure during daily life over 24 hours, and home blood pressure self-measurement are widely used. Home blood pressure is particularly useful for distinguishing 'white-coat hypertension' (elevated only in the clinic) from 'masked hypertension' (normal in the clinic but elevated in daily life). Recommended principles include resting for at least 5 minutes before measurement, keeping the arm at heart level, and taking repeated measurements at the same time of day.

Classification of Blood Pressure Levels

The Korean Society of Hypertension and international guidelines generally classify blood pressure as follows.

  • Normal blood pressure: systolic below 120 mmHg and diastolic below 80 mmHg
  • Elevated blood pressure: systolic 120–129 mmHg and diastolic below 80 mmHg
  • Prehypertension: systolic 130–139 mmHg or diastolic 80–89 mmHg
  • Stage 1 hypertension: systolic 140–159 mmHg or diastolic 90–99 mmHg
  • Stage 2 hypertension: systolic 160 mmHg or higher or diastolic 100 mmHg or higher
  • Hypotension: generally systolic below 90 mmHg or diastolic below 60 mmHg

Hypertension

Hypertension is one of the most common chronic diseases worldwide and is often called the "silent killer" because it frequently causes no obvious symptoms. Essential (primary) hypertension of unknown cause accounts for more than 90% of cases, while the remainder is secondary hypertension caused by kidney disease, endocrine disorders, medications, and other factors. If left untreated, it greatly increases the risk of stroke, heart failure, coronary artery disease, chronic kidney disease, retinopathy, and other conditions. Treatment combines lifestyle modification (a low-salt diet, regular exercise, weight loss, smoking cessation, and moderation in alcohol consumption) with antihypertensive drugs when necessary.

Hypotension

Hypotension is a state in which blood pressure is excessively low, so the brain and major organs do not receive sufficient blood flow; symptoms include dizziness, fainting, fatigue, and reduced concentration. Representative types include orthostatic hypotension (a sudden drop in blood pressure upon standing), postprandial hypotension, and neurally mediated hypotension, and causes may include dehydration, hemorrhage, heart disease, and endocrine abnormalities. Asymptomatic hypotension does not require special treatment, but when symptoms accompany it, measures such as fluid and salt intake, compression stockings, and medication adjustment are considered.

Factors Affecting Blood Pressure

Blood pressure is affected by various factors, including age, genetics, obesity, salty food intake, smoking, alcohol consumption, stress, lack of sleep, caffeine, and physical activity level. Season (rising in winter), time of day (the 'morning blood pressure surge' that rises sharply in the morning), temperature changes, and medications being taken are also important variables. In particular, the morning blood pressure surge is closely associated with cardiovascular events, so its management is emphasized.

Latest Trends

In 2024–2025, home blood pressure and continuous blood pressure monitoring based on wearable devices are spreading rapidly. Technology that estimates blood pressure without a cuff using smartwatch and ring-type sensors has entered the commercialization stage, and personalized blood pressure management services using it are attracting attention. In addition, domestic and international guidelines continue to emphasize strict blood pressure targets (systolic below 130 mmHg), and in hypertension treatment, the initial use of combination drugs (combining two or more components) rather than monotherapy is increasing. Furthermore, interventional treatments such as renal denervation are being re-examined for patients with drug-resistant hypertension, and cases of integrating digital health and AI-based risk prediction models into chronic disease management are increasing. With an aging population and Westernized dietary habits, the domestic prevalence of hypertension is steadily increasing, making early detection and consistent management increasingly important.

Related Topics

  • [[Hypertension]]
  • [[Hypotension]]
  • [[Cardiovascular disease]]
  • [[Stroke]]
  • [[Myocardial infarction]]
  • [[Chronic kidney disease]]
  • [[Lifestyle disease]]