Which vital sign is directly measured using a sphygmomanometer?

The vital sign that is directly measured using a sphygmomanometer is blood pressure. This device consists of an inflatable cuff that is placed around the upper arm and is connected to a pressure gauge. When the cuff is inflated, it temporarily stops the flow of blood through the brachial artery. As the cuff gradually deflates, the practitioner listens for specific sounds (known as Korotkoff sounds) through a stethoscope placed over the artery. The pressure at which these sounds are first heard represents the systolic blood pressure, while the pressure at which the sounds disappear indicates the diastolic blood pressure.

Understanding how blood pressure is measured is crucial for assessing cardiovascular health, as it provides important information about the force of blood against the walls of the arteries. The sphygmomanometer is a standard tool in both clinical settings and home monitoring, making it essential for healthcare personnel to be proficient in its use.