Hypertension

Hypertension is a condition in which blood pressure in the blood vessels remains persistently elevated. Blood pressure is measured by two numbers: the systolic (upper), which represents the pressure when the heart contracts, and the diastolic (lower), which represents the pressure when the heart rests. The reading is expressed in millimeters of mercury (mmHg), for example 120/80.

Hypertension often has no clear symptoms over a long period, which is why a person typically becomes aware of it only through measurement. If left untreated, it increases the risk of heart disease, stroke (bleeding in the brain), kidney disease, and damage to the eyes.

Measurement and definition

Blood pressure is measured using an instrument called a sphygmomanometer, with an inflated cuff. The definition of hypertension depends on guidelines from health authorities, but generally it is considered present when multiple readings taken on different days exceed normal levels. A single elevated reading is not sufficient for diagnosis; healthcare providers typically repeat measurements, and in some cases use 24-hour monitoring devices.

Causes and risk factors

In most cases no single cause can be identified; this is known as essential (primary) hypertension. Contributing factors include genetics, age, body weight, high salt intake in food, physical inactivity, smoking, alcohol use, and chronic stress. A small proportion results from another disease such as kidney disease or hormonal disorders, known as secondary hypertension.

Management

Management begins with lifestyle changes: reducing salt intake, eating a diet rich in vegetables, regular physical activity, weight reduction, and quitting smoking and reducing alcohol consumption. When this proves insufficient, various medications are used that work through different mechanisms, such as diuretics and vasodilators. Treatment is typically long-term, and blood pressure requires continuous monitoring.