Dismiss Modal

Types

Understanding Heart Valves

Choose a preferred language

The heart has four valves. They are the aortic, pulmonary, tricuspid, and mitral valves. The valves open and close to keep blood moving in the right direction through the heart. Blood moves through the heart as it beats. With each squeeze, the valves open and close to keep blood moving forward. In this way, valves keep blood moving as well as possible through the heart. They also prevent backflow.

Cross section of heart showing four valves.

When the heart relaxes between beats:

  • Oxygen-rich blood from the lungs fills the left atrium.

  • Oxygen-poor blood from the body fills the right atrium.

When the atria beat:

  • The left atrium squeezes. This pushes blood through the mitral valve into the left ventricle.

  • The right atrium squeezes. This pushes blood through the tricuspid valve into the right ventricle.

When the ventricles beat:

  • The left ventricle squeezes. This pushes blood through the aortic valve out to the heart arteries, the brain, and body.

  • The right ventricle squeezes. This pushes blood through the pulmonary valve to the lungs.

Diagram of three cross-sectioned hearts showing blood flow during heartbeats.

© 2000-2025 The StayWell Company, LLC. All rights reserved. This information is not intended as a substitute for professional medical care. Always follow your healthcare professional's instructions.

Find a cardiac specialist

Because every beat matters, our cardiac doctors are dedicated to providing care like no other can.

Browse heart doctors

Related Articles
Read article
Heart Health
Cardiac Conditions and Diseases

Detailed information on the most common cardiovascular diseases, including full-page descriptions detailing the most common types of heart disease, related symptoms, diagnostic, implantable cardioverter defibrillators, ICDs, and treatment information

Read article
Heart Health
Unstable Angina

There are 2 types of angina, stable and unstable. Stable angina occurs at certain times and can often be managed. Unstable angina occurs at uncertain times. It may not get better with the usual forms of treatment for angina. It is a warning that a heart attack (acute myocardial infarction) is possible in the near future.

Read article
Heart Health
Left-sided heart failure

Left-sided heart failure can cause shortness of breath and trouble breathing. Learn about treatment and home care for this condition.

Read article
Heart Health
Heart Valve Problems: Aortic Stenosis

Aortic stenosis means your aortic valve has a problem opening. The left ventricle has to work harder to push the blood through the valve. In some cases, this extra work will make the muscle of the ventricle thicken. This type of stenosis can quickly get worse.