bloodpressure

Blood pressure is the force exerted by circulating blood on the walls of arteries. It is expressed as systolic pressure over diastolic pressure, usually measured in millimeters of mercury (mmHg). Systolic pressure reflects arterial pressure during heart contraction, while diastolic pressure reflects pressure during relaxation between beats. Normal values for adults are typically below 120/80 mmHg. Elevated values begin around 120-129 systolic with diastolic below 80. Hypertension is typically defined as sustained blood pressure at or above 130/80 mmHg in many guidelines, with stage 2 defined as at least 140/90 mmHg. Isolated systolic hypertension occurs when systolic is high while diastolic remains normal or low.

Measurement methods: BP can be measured with a manual sphygmomanometer and stethoscope or with automated devices. For accuracy, the patient should be seated with back supported, arm supported at heart level, feet uncrossed, and the cuff sized appropriately. Rest for several minutes; avoid caffeine or smoking for at least 30 minutes before measurement; take at least two measurements and average them. Home blood pressure monitoring and ambulatory BP monitoring provide data across daily activities.

Factors influencing BP include age, weight, physical activity, stress, salt intake, medications, and circadian variation. Persistent high or low blood pressure can indicate health risks, including cardiovascular disease, stroke, and kidney disease. Management commonly combines lifestyle changes, such as diet, exercise, and limiting alcohol and sodium, with pharmacological therapy when indicated, under medical supervision.