What does blood pressure measure?

Blood pressure specifically measures the pressure exerted by circulating blood on the walls of the arteries. This measurement is crucial for understanding cardiovascular health, as it reflects how well blood is able to flow throughout the body. Blood pressure readings consist of two values: systolic pressure, which measures the pressure when the heart beats and pumps blood, and diastolic pressure, which measures the pressure in the arteries when the heart is at rest between beats. Monitoring blood pressure is vital for diagnosing conditions such as hypertension, which can lead to serious health issues like heart disease and stroke.

In contrast, the other options touch on related concepts but do not accurately define what blood pressure measures. The volume of blood circulating in the arteries pertains to blood volume, not pressure. The resistance of blood flow in the veins relates to hemodynamics but is not a direct measure of blood pressure. Lastly, the amount of oxygen transported by hemoglobin deals with respiratory function and gas exchange, which is separate from the mechanical aspect of blood pressure.