A blood pressure cuff (also called a sphygmomanometer cuff or BP cuff) is the inflatable component of a blood pressure measurement device, placed around the upper arm or occasionally the wrist to measure arterial blood pressure. When inflated, the cuff temporarily occludes blood flow in the brachial artery; as it deflates, the pressure at which blood flow returns is detected either by a stethoscope (manual technique), an electronic sensor (automated device) or a mercury or aneroid gauge.
Blood pressure readings consist of two numbers: systolic pressure (the peak pressure when the heart contracts) and diastolic pressure (the pressure between beats when the heart is relaxed), expressed in millimetres of mercury (mmHg). A standard adult reading is recorded as, for example, 120/80 mmHg. Cuff size matters: a cuff that is too small will overestimate blood pressure, and one that is too large will underestimate it. Most adults use a standard cuff, but larger and smaller sizes are available.
For survivors of sudden cardiac arrest, regular blood pressure monitoring is an important part of ongoing care. Many are prescribed antihypertensive medications, and monitoring ensures blood pressure is within the target range, typically below 130/80 mmHg for those at high cardiovascular risk. In the intensive care unit, critically ill post-arrest patients require continuous invasive blood pressure monitoring via an arterial line rather than a cuff, as beat-to-beat accuracy is essential for guiding vasopressor therapy.
Home blood pressure monitors are widely available and recommended for people with hypertension or cardiovascular disease. The British and Irish Hypertension Society (BIHS) maintains a list of validated home monitors. Taking readings in the morning before medication and recording results in a log helps the GP or cardiology team assess trends and adjust treatment. White coat hypertension, where blood pressure is higher in clinical settings than at home, is also best detected through home monitoring.
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