Our heart pumps blood around our body and to ensure that blood keeps moving in one direction, there are valves within our heart. When these valves shut (like a door) they produce a sound which is heard by the doctor as "Lub Dub". However, if the valves are narrowed or have a leak in them and thus leak, an additional sound is heard called a murmur. This sound is produced by blood being forced across a narrowed valve or by blood leaking back through a gap in the valve as it tries to close.

The murmur may also occur if blood moves rapidly through normal valves. This is normal in childhood or in patients with fast heart rates which occur in pregnancy, fever, hyperthyroid states or anaemia. Murmurs which occur when the heart contracts are called systolic murmurs and those that occur when the heart relaxes are called diastolic murmurs.

As mentioned some murmurs occur in normal hearts if the blood moves quickly. Your doctor assesses your murmur and may perform tests to work out if there is a problem with one of your heart valves. Sometimes, the murmur is innocent which means it does not signify any major heart problem. If there is a problem with one of your valves your doctor may decide that no treatment is needed or that you would benefit from drugs or some form of surgery to fix the problem.