A sphygmomanometer is a medical device used to measure blood pressure. It consists of an inflatable cuff, a pressure gauge, and sometimes a stethoscope. Here’s how it works: Cuff Inflation: The cuff is wrapped around the upper arm, and it is inflated with air. As the cuff inflates, it temporarily cuts off the blood flow in the artery. Pressure Release: The air in the cuff is slowly released, allowing blood to flow through the artery again. As the blood flows, it creates turbulent sounds in the artery. Listening for Sounds: If a stethoscope is used, the healthcare provider places it over the artery (typically the brachial artery in the upper arm) and listens for the sounds of blood flowing. These sounds are known as Korotkoff sounds. Blood Pressure Measurement: The point at which the healthcare provider first hears the Korotkoff sounds (Phase I) represents the systolic blood pressure, which is the pressure when the heart is contracting and pumping blood. The point at which the sounds disappear (Phase V) represents the diastolic blood pressure, which is the pressure when the heart is at rest between beats. The pressure gauge on the sphygmomanometer provides a numerical value for both the systolic and diastolic blood pressure in millimeters of mercury (mmHg). Blood pressure is typically expressed as systolic over diastolic (e.g., 120/80 mmHg). Accurate measurement of blood pressure is crucial in diagnosing and managing various medical conditions, such as hypertension (high blood pressure), and is an essential part of routine medical examinations. Sphygmomanometers come in various types, including manual ones that require a healthcare provider to operate, and automatic or digital ones that can be used by individuals at home for self-monitoring.