What is a Heart Murmur?

Heart murmurs are extra or unusual sounds heard during a heartbeat. Sometimes they sound like a whooshing or swishing noise. Doctors can hear these sounds and heart murmurs using a stethoscope.



The two types of heart murmurs are innocent (harmless) and abnormal.


Innocent heart murmurs:

Why some people have innocent heart murmurs and others do not is not known. These murmurs are common in healthy children and do not pose a health threat. Children do not need to take any medicine or be careful in any special way. Extra blood flow through the heart also may cause innocent heart murmurs. After childhood, the most common cause of extra blood flow through the heart is pregnancy. This is because during pregnancy, women's bodies make extra blood. Most heart murmurs that occur in pregnant women are innocent.

Abnormal heart murmurs:

People with abnormal heart murmurs may have signs or symptoms of heart problems. Most abnormal murmurs in children are caused by congenital heart defects. They change the normal flow of blood through the heart. Sometimes a heart murmur indicates a problem with the child's heart, such as, a hole in the heart, a leak in a heart valve or, a narrow heart valve. In adults, abnormal heart murmurs most often are caused by acquired heart valve disease. Certain conditions can stretch and distort the heart valves. Some examples are; infections, heart attack, advanced high blood pressure, atherosclerosis, heart failure, and aging can cause heart valve disease.

What are the Signs and Symptoms of an Abnormal Heart Murmur?

People who have abnormal heart murmurs may have signs or symptoms of the heart problems causing the murmurs. Signs and symptoms depend on the problem causing the heart murmur and its severity.

    • Poor eating and abnormal growth (in infants)

    • Shortness of breath, which may occur only with physical exertion

    • Excessive sweating with no clear cause

    • Chest pain

    • Dizziness or fainting

    • A bluish color on the skin, especially on the fingers and lips


If a doctor suspects a problem, he or she may choose to refer the child to a cardiologist. The cardiologist will carefully listen to the child's heart with a stethoscope to find out whether a murmur is innocent or abnormal. He or she will listen to the loudness, location, and timing of the murmur. The doctor may request for additional tests to be performed. These tests include chest X-ray, electrocardiogram (EKG or ECG) or echocardiogram.


Innocent (Harmless) Heart Murmurs

Healthy children who have innocent (harmless) heart murmurs don't need treatment. Their heart murmurs aren't caused by heart problems or other conditions. Pregnant women who have innocent heart murmurs due to extra blood volume also don't need treatment. Their heart murmurs should go away after pregnancy.

Abnormal Heart Murmurs

If an adult or a child has an abnormal heart murmur, the doctor will recommend treatment for the disease or condition causing the murmur. Currently, no medicines can cure heart valve disease. However, lifestyle changes and medicines can treat symptoms and help delay complications. Eventually, though, the patient may need surgery to repair or replace a faulty heart valve. Some heart murmurs occur because of an illness outside of the heart. The heart is normal, but an illness or condition can cause blood flow that's faster than normal. Examples of this type of illness include fever, anemia , and hyperthyroidism. Treating these conditions should make the heart murmur go away.

Other Names for a Heart Murmur

Innocent Heart Murmurs
  • Benign heart murmurs.

  • Flow murmurs

  • Functional heart murmurs

  • Mammary souffle (heard in some pregnant women because of increased blood flow to the breasts.)

  • Normal heart murmurs

  • Physiologic heart murmurs

  • Still's murmurs

  • Venous hums.

Abnormal Heart Murmurs

  • Pathologic heart murmurs

Heart Murmur. (2010, August). National Heart, Lung and Blood Institute: National Institutes of Health. Retrieved March 31,2011 from http://www.nhlbi.nih.gov/health/dci/Diseases/heartmurmur/hmurmur_what.html

Department of Public Health
Riverside County Public Health Nursing / MCAH
Health Administration Building | 4065 County Circle Drive, Riverside, CA 92503
(951) 358-5438 | Fax (951) 358-4762