Heart disease is a leading cause of death for both men and women and a serious health problem that affects millions of people worldwide. There are many things you can do to reduce your risk of developing heart disease. To learn more on how to help maintain the health of your heart visit: www.merck.com/disease/heart

It is important to learn about how your body works. A good place to start is with your heart, blood, and blood vessels. Why? Because these are the components that move the substances your body makes to where they are required. This site is dedicated to teaching you more about the important roles your heart, blood vessels, and blood play within your body.

Your cardiovascular system transports important substances around your body. Your heart, blood, and blood vessels are all components of the cardiovascular system.

Your heart is a muscular pump that pushes blood to all parts of your body. This organ, which is barely larger than the size of your closed fist, provides the force that powers the cardiovascular system.

The blood vessels, which include arteries, arterioles, capillaries, venules, and veins, are the portals and pathways through which blood travels in your body.

Your cells and organs require oxygen to live. Your blood is responsible for bringing the oxygen you breathe in from your lungs to the cells and organs that need it. In addition, it carries other important substances such as hormones and nutrients around your body and removes the waste your cells produce.

Your heart is not a perfect machine and may not always work properly. This section will introduce you to some of the most common cardiovascular problems people experience, such as hypertension, heart attack, and congestive heart failure.