Heart Murmur: Causes and Symptoms

What is a heart murmur?

A heart murmur is not a disease, but an extra whooshing or swishing sound the heart makes in addition to the normal heart beats. Murmurs are very common in childhood.

Is a heart murmur dangerous?

Sometimes, a murmur can mean there is an issue with how the heart is built. For many kids, however, murmurs are benign (not serious) and are associated with a normal heart.

What causes heart murmurs?

In most cases, the murmur is the result of blood flowing in and out of the heart. These are called innocent, benign or functional murmurs. Pathologic murmurs are caused by blood flowing through abnormal heart structures.

What should my child see a doctor for a heart murmur?

Your child should see a doctor if she/he has a heart murmur AND shows any of these symptoms:

• Breathes faster than normal
• Sweats more than normal
• Grows slower than normal (also called failure to thrive)
• There is a suspicion of genetic abnormalities

Rev.6/2018. Mass General for Children and Massachusetts General Hospital do not endorse any of the brands listed on this handout. This handout is intended to provide health information so that you can be better informed. It is not a substitute for medical advice and should not be used to treatment of any medical conditions.