What does blood pressure measure?

Blood pressure specifically measures the force that blood exerts against the walls of the arteries as the heart pumps it through the circulatory system. This force is essential for maintaining adequate blood flow to various organs and tissues, delivering oxygen and nutrients, and helping to remove waste products. Blood pressure is typically expressed in two values: systolic pressure, which occurs when the heart beats and pumps blood, and diastolic pressure, which occurs when the heart is at rest between beats.

Understanding blood pressure is crucial for assessing cardiovascular health, as abnormal values can indicate various health issues, such as hypertension or hypotension, both of which can have serious implications for health. The other options describe different physiological factors but do not pertain to the primary definition of blood pressure. For instance, while blood volume is related to blood pressure, it is not the same measurement. Similarly, the speed of blood flow and the amount of oxygen in the blood, while important aspects of cardiovascular health, do not define blood pressure itself.