Heart murmurs are very common in children - about three in every ten children will have a heart murmur from time to time. Most of these children have a murmur with a particular sound that we call an Innocent Murmur. In these children, the heart is completely normal heart and it is not a sign of heart disease. Innocent Murmurs are especially noticeable if a child is unwell with a fever. Generally they become harder to hear as children grow older, but are often still heard in adults. They have been given several names that all mean the same thing - innocent, vibratory, functional, Stills (after Dr Still who described it) or venous hum.
There are various theories why normal hearts may make a noise, but the most likely explanation is that as the blood circulates through the heart and arteries, it causes minor vibrations which make the noise. This is similar to the mechanism that generates the noise water often makes when it comes out of the tap. This also explains why Innocent Murmurs are louder when the child has a fever as the heart beats faster, blood circulates quicker and the vibrations are louder.
A heart murmur can be heard when a doctor listens with a stethoscope. Most of these children have a murmur with a particular sound that we call an Innocent Murmur.
If you have been told that your child has an Innocent Murmur, it is important for you to realise that your child does not have a heart problem. They can take part in all activities and sports. It is also not necessary for them to have antibiotics before they visit a dentist. Further medical check-ups are unnecessary.