Your Heart Is About the Size of Your Fist

You can get a rough idea of the size of your own heart by looking at your hand. The National Heart, Lung, and Blood Institute, part of the US National Institutes of Health, describes the heart as an organ about the size of your fist that pumps blood through your body. The comparison is to your own fist, so it scales with the person, and it is an approximation and not a measurement. The institute explains that the heart is made up of multiple layers of tissue and sits at the center of the circulatory system. That system is a network of blood vessels, such as arteries, veins and capillaries, that carries blood around the body. The heart is the pump that keeps the blood in that network moving.