Which vital sign measures the force of blood against the artery walls?

Blood pressure is the vital sign that specifically measures the force of blood against the walls of the arteries. This measurement is crucial because it reflects how well the heart is functioning and how effectively blood is circulating throughout the body. High blood pressure, or hypertension, can lead to serious health issues, including heart disease and stroke, while low blood pressure, or hypotension, can cause fainting and shock.

Blood pressure is typically expressed in two numbers: systolic pressure (the force of blood during heartbeats) over diastolic pressure (the force of blood when the heart is resting between beats). This distinction provides insights into cardiac function and vascular health.

The other options, such as pulse rate, oxygen saturation, and respiratory rate, measure different physiological parameters. Pulse rate indicates the number of heartbeats per minute; oxygen saturation measures the amount of oxygen in the blood; and respiratory rate counts the number of breaths taken in a minute. Each of these vital signs provides valuable information about a person's health but does not specifically measure the force of blood against arterial walls.