A murmur is an abnormal noise heard by a doctor when listening to your child's heart. Normally we hear two soft noises for each heart beat and it sounds like 'lub-dub'. Occasionally when listening to a child's heart we hear an extra soft noise or a whoosing sound as if the blood is rushing quickly through a narrow space - this is called a murmur. These murmurs can be normal - especially when Children have a high temperature or are crying. Your doctor will evaluate this murmur with a full examination of the heart and lungs before deciding whether to simply see you again or refer you (often just for reassurance) to a paediatrician with expertise in Cardiology. If we also hear the murmur then a simple scan (echocardiogram) should help identify the cause or reassure us that it is just from an active heart.