What do heart valves do?

Dr. Mehmet Oz, MD
Cardiology (Cardiovascular Disease)
Heart valves separate the four chambers of the heart that collect and pump blood, and control the direction of blood flow. Watch this animation to see how the heart valves work.

Dr. Michael Roizen, MD
Internal Medicine
Your heart valves play a key and surprisingly basic role in the never-ending cycle of blood through the heart: They are doormen that keep the blood from getting lazy and retracing its journey, leaking backward into the chambers it has just left.

There are valves between each atrium and ventricle -and between each ventricle and the blood vessel that leaves it. As the blood swishes through, the valves slam shut, producing what we hear on TV as a heartbeat. (Doctors listening through the stethoscope are trying to hear how your heart valves are functioning; the "crispness of the sound" describes how well the valves are coming together; timing differences between the valves' sounds can indicate electrical differences between the two sides of the heart, and murmurs can indicate the size of the valve openings or any leakage through the valves.)

The valves are crucial to the heart's functioning because a little leakage within the heart is a dangerous thing. If the valves are inefficient or malformed, if they waver rather than slam open and closed, blood can pool in the atrium, just like with atrial fibrillation . And when blood pools for any amount of time, it is programmed to do one thing: clot. Inside the heart, a clot leads to disaster.
YOU: The Owner's Manual, Updated and Expanded Edition: An Insider's Guide to the Body that Will Make You Healthier and Younger

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YOU: The Owner's Manual, Updated and Expanded Edition: An Insider's Guide to the Body that Will Make You Healthier and Younger

Between your full-length mirror and high-school biology class, you probably think you know a lot about the human body. While it's true that we live in an age when we're as obsessed with our bodies as...

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Heart and Circulatory System

Heart and Circulatory System

Your circulatory system is made up of your heart and three main types of blood vessels -- arteries, veins and capillaries. Your heart is at the center of the system, acting as a pump to distribute nutrient- and oxygen-rich blood t...

hrough your body; it then takes away carbon dioxide and other waste your body doesn't need. Signs of poor circulation include cold hands and feet, numbness, dizziness, migraines, varicose veins and pain in your feet or legs. Untreated, poor circulation can lead to stroke, high blood pressure, kidney damage and other diseases. Learn more about your heart and circulatory system with expert advice from Sharecare.

Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.