Patient Care

Innocent Murmur (Children)

What is Innocent Murmur in Children?

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.

Innocent Murmurs are not the only type of murmur. Some murmurs are caused by blood passing through a hole or a narrowed or leaky valve. These, however, make a different sound to Innocent Murmurs and are usually easy to distinguish. If there is any doubt, a heart scan test will be able to confirm whether the murmur is innocent or not.

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.

How is Innocent Murmur in Children diagnosed?

​​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.

Caring for children with 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.

Dental Care

Children and adults with congenital heart disease are at an increased risk of having a heart infection. While this is rare, the chances of it occurring can be reduced by taking precautions.

Infections in the heart can occur for no apparent reason but are more common if the teeth are rotten. Germs spread into the blood stream and infect the heart. Good dental hygiene is therefore important as are regular visits to the dentist.

If dental treatment is required, some procedures can cause germs to spill into the blood and infect the heart.

It is therefore important that the dentist is informed about the heart condition before treatment. The usual method of avoiding this problem is to give a single dose of antibiotics one hour prior to the treatment to kill any germs beforehand.


Exercise is important even in those with heart disease. It improves the heart function and general sense of well being. It is also associated with increased life expectancy, and a reduced risk of heart disease in later life. In addition, physical activity helps with controlling weight and reducing blood pressure.

There are different types of exercise. In static exercise, the muscles contract but there is little joint movement, e.g. weight lifting. In dynamic exercise, the muscles contract and also move the joints, e.g. running. Each places a different stress on the body and cardiovascular system. In general, most types of sports are a mix of the two.

Children usually take part in more rigorous exercise at school as they grow older. In Singapore, physical education (PE) tends to teach games skills rather than competitive sports. However pupils may take sport for their co-curricular activities (CCA) where training is more intense and competitive. Training for the NAPFA test is also intensive, and some pupils with heart problems may have difficulty with the 2.4km run as they often perform less well at endurance type activities.

As always, parents should seek the doctor's advice when deciding how much exercise and to what level is safe, particularly as there are no published guidelines for activity levels in children.


Most children with heart disease can have all the normal vaccinations at the appropriate time.

However, some children with an immune deficiency (DiGeorge syndrome or an isomerism), and those who are receiving immunosuppression, for example, following transplantation, require a different vaccination schedule.

Travel Advice

Before travelling anywhere unusual or a long distance make sure that your child has:

  • Had a recent medical check up
  • Appropriate insurance cover
  • An adequate supply of medicine
  • Access to quality health care at your travel destination
  • Relevant documentation about their heart condition

Those with cyanotic heart disease ("blue" due to reduced oxygen in the blood) can still travel, but aircraft at altitude have less oxygen in the air than at ground level, so the blueness may be more apparent. This does not usually cause symptoms but, if necessary, airlines can arrange for additional oxygen to be available on the aircraft.

For long aircraft flights, it is sensible to use the support stockings and take aspirin or an equivalent unless your doctor advises against it.


Special diets are not normally necessary for those with heart disease. As with everyone it is important to have a balanced diet and not to eat to excess. It is, however, important to maintain a normal weight. Excess weight means more work for the heart.


Most children with heart disease are no more prone to infections than any other children. Some however are likely to get chest infections - particularly those with holes in the heart (ASD, VSD, PDA).

In addition, some heart diseases are also associated with an immune deficiency, and infections therefore are more common. The majority of childhood infections are viruses and get better without antibiotics. In case of amu doubt, professional medical help should be sought, and the doctor will decide if antibiotics are necessary.


Most children with heart disease do not require medication. Some however need them to:

  • Reduce the body fluids
  • Assist the pumping action
  • Control rhythm problems
  • Thin the blood

The majority of these medicines have been used for many years and are very safe, but like all drugs, side effects may occur. This is especially if there is another illness or a change in other medication. If unusual symptoms or side-effects occur whilst on medication, it is important to inform the doctor immediately.

Find A Doctor

Click here to access our Find A Doctor directory for a list of doctors treating this condition across our NUHS institutions.

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National University Health System
  • National University Hospital
  • Ng Teng Fong General Hospital
  • Alexandra Hospital
  • Jurong Community Hospital
  • National University Polyclinics
  • Jurong Medical Centre
  • National University Cancer Institute, Singapore
  • National University Heart Centre, Singapore
  • National University Centre for Oral Health, Singapore
  • NUHS Diagnostics
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  • Yong Loo Lin School of Medicine
  • Faculty of Dentistry
  • Saw Swee Hock School of Public Health
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