In medical terminology, "cardiac output" is the volume of blood which is pumped by a single ventricle of the heart per minute. Its unit is generally held to be milliliters per minute (ml/minute). For an average adult, the normal cardiac output value is 4,900 ml/minute while resting. During periods of extreme physical exertion, cardiac output levels may rise as high as 30,000 ml/minute.

On the other hand, "total peripheral resistance" is a value which refers to the combined resistance of all the arterioles in the lungs, which are the main 'resistance vessels' present in the human body, and cannot relieve arterial pressure completely. During a contraction of the heart, the rate at which blood enters the arteries is faster than the rate at which it leaves, causing the arteries to undergo expansion. The total peripheral resistance is calculated by dividing a body's mean arterial pressure (the normal blood pressure of the body, or the mean arterial pressure during one cardiac cycle) with the cardiac output value.

In case of hypertension, the total peripheral resistance is noticeably larger, since the mean arterial pressure is much greater in case of hypertension patients.