Which vital sign is primarily measured by a sphygmomanometer?

A sphygmomanometer is a device specifically designed to measure blood pressure. This vital sign indicates the force exerted by circulating blood on the walls of blood vessels, and it is expressed in millimeters of mercury (mmHg) as two figures: systolic pressure over diastolic pressure. Systolic pressure occurs when the heart beats and pumps blood, while diastolic pressure is measured when the heart is at rest between beats.

Measuring blood pressure is essential in clinical settings because it helps assess cardiovascular health, diagnose hypertension, and monitor the response to various treatments. Other vital signs such as heart rate, oxygen saturation, and respiratory rate are assessed using different methods and tools, making the sphygmomanometer unique in its purpose. Therefore, blood pressure is the vital sign most closely associated with the use of this particular instrument.