Skip to content

Heart Disease Health Center

Select An Article
Font Size

What Are Heart Murmurs?

Most heart murmurs are innocent, which means your heart is healthy, and you don't need any treatment.

But there are exceptions. Heart murmurs can be linked to a damaged or overworked heart valve. Some people are born with valve problems. Others get them as part of aging, or from other heart problems.

Recommended Related to Heart Disease

The Post-Quadruple-Bypass Workout

Lynn Swassing was just 48 years old, the mother of two sons in high school and one daughter in college, when she had a heart attack in 1987. She underwent quadruple bypass surgery and was hospitalized for nearly six weeks. Every single day, at some point, the hospital had an exercise specialist at the foot of my bed, she recalls. They told me, if you don't get active, you won't make it. No way,was Swassing's first thought. The full-time mom had never been on a treadmill in her life, and she...

Read the The Post-Quadruple-Bypass Workout article > >

The  "murmur" is the sound of blood flowing. It may be passing through a heart valve that has problems, for instance. Or it may be that a condition is making your heart beat faster, forcing your heart to handle more blood quicker than normal. Heart murmurs are the result.


Common conditions can make your heart beat faster and lead to heart murmurs. It can happen if you're pregnant or if you have:

  • Anemia
  • High blood pressure
  • Overactive thyroid
  • Fever

It could also be a problem with a heart valve. The valves close and open to let blood flow through the heart's two upper chambers (the atria) and two lower chambers (the ventricles). Valve problems include:

Mitral valve prolapse: Normally, your mitral valve closes completely when the lower left chamber of your heart contracts. It stops blood from flowing back into the upper left chamber. If part of that valve balloons out so that it doesn't close properly, you have mitral valve prolapse. This causes a clicking sound as your heart beats. It's fairly common and it's often not serious. But it can lead to the blood flowing backward through the valve, also called regurgitation.

Mitral valve or aortic stenosis: Your mitral or aortic valves are on the left side of your heart. If they narrow, which doctors call stenosis, your heart must work harder to pump blood out to the rest of your body. If untreated, it can wear out your heart and can lead to heart failure. You might be born with this condition. It can also happen as part of aging, or as a result of scarring from infections, such as rheumatic fever.

Aortic sclerosis and stenosis: One in three elderly people have a heart murmur due to the scarring, thickening, or stiffening (which doctors call sclerosis) of the aortic valve, although it hasn't narrowed. It's usually not dangerous, since the valve can work for years after the murmur starts. Aortic sclerosis is usually seen in people who have heart disease. But over time, the valve can narrow, also called stenosis. This can lead to chest pain, shortness of breath, or passing out. In some cases, the valve may need to be replaced.

Mitral or aortic regurgitation: In this case, regurgitation means the blood is going the wrong way through the mitral valve or the aortic valve. To counteract this backflow, the heart must work harder to force blood through the damaged valve. Over time, this can weaken or enlarge the heart and can lead to heart failure.

Congenital heart defects: About 25,000 babies are born each year with heart defects, such as holes in heart walls or abnormal heart valves. Surgery can correct many of these problems.

Next Article:

Today on WebMD

x-ray of human heart
A visual guide.
atrial fibrillation
Symptoms and causes.
heart rate graph
10 things to never do.
Compressed heart
empty football helmet
red wine
eating blueberries
Simple Steps to Lower Cholesterol
Inside A Heart Attack
Omega 3 Sources
Salt Shockers
lowering blood pressure