Health Resources

Innocent Murmur (Children)

Signs & Symptoms

A heart murmur refers to an audible sound detected with a stethoscope during a heart examination. Many children have a specific type of heart murmur known as an innocent murmur.

What causes it

The prevailing theory is that as blood circulates through the heart and arteries, it causes minor vibrations, creating the murmur sound. This is akin to the noise water makes flowing from a tap. This theory also explains why innocent murmurs are more pronounced when the child has a fever, as the accelerated heart rate and blood circulation amplify these vibrations.

About the condition

Heart murmurs are common in children, with about three in every ten experiencing them occasionally. Most are identified as innocent murmurs, indicating a completely normal heart without signs of heart disease. Innocent murmurs are more noticeable during illness or fever. While they often become less audible as children grow, they can still be present in adults. These murmurs are known by various names, including, innocent, vibratory, functional, Stills (after Dr Still who described it) or venous hum.

Not all murmurs are innocent murmurs. Some are caused by blood passing through an abnormality like a hole, a narrowed passage or a leaky valve. These murmur sounds different from innocent murmurs and are usually distinguishable. If cases of uncertainty, a heart scan can confirm whether the murmur is innocent.
Diagnosis and Treatment Options

Endocarditis prophylaxis is not necessary for an innocent murmur.

Care Tips

Dental Care

Good dental hygiene is essential, especially for children and adults with congenital heart disease, as poor dental health can lead to infections spreading to the heart. Therefore, regular dental check-ups are crucial.

Inform your dentist about the heart condition before any treatment. To prevent germs from entering the bloodstream and affecting the heart, a single dose of antibiotics may be given one hour prior to dental procedures.


Exercise is beneficial, even for those with heart conditions. It improves heart function, overall well-being and is associated with increased life expectancy and reduced heart disease risk in later life. It also aids in weight control and blood pressure reduction.

Different types of exercise, such as static (e.g., weight lifting) and dynamic dynamic (e.g., running), have varying impacts on the body and heart. Children with heart conditions should consult their doctor to determine safe levels and types of exercise, especially in school settings where physical activities can be intensive.


Most children with heart disease can follow standard vaccinations schedule. However, those with immune deficiencies, such as DiGeorge syndrome or an isomerism, or those who are receiving immunosuppression, such as post-transplantation, may require a modified vaccination schedule.

Travel Advice

Before travelling, especially long distances or to unusual destinations:

  • Have a recent medical check-up
  • Ensure appropriate insurance coverage
  • Carry an adequate supply of medication
  • Be informed about the local healthcare quality and accessibility
  • Carry relevant documentation about the heart condition  For cyanotic heart disease patients, be aware of potential oxygen needs during flights
  • Use support stockings and take aspirin or equivalent unless your doctor advises against it


Special diets are not normally required for those with heart disease, but a balanced one is important. Maintaining a normal weight is crucial as excess weight increases the heart’s workload.


Children with heart disease are generally not more prone to infections, although some may be susceptible to chest infections or have associated immune deficiencies, particularly those with holes in the heart (ASD, VSD, PDA). Viral infections are common and usually resolve without antibiotics, but medical advice should be sought in case of uncertainty.


Not all children with heart disease require medication. Those who do may need it for fluid reduction, aiding heart pumping, rhythm control or blood thinning.

While these medications are generally safe, side effects can occur, especially with other illnesses or medication changes. Any unusual symptoms or side-should be promptly reported to the doctor.


Most women with heart disease can have a normal pregnancy and delivery. Exceptions may include those with severe cyanosis or pulmonary hypertension, where pregnancy can pose significant risks.

It is essential to seek medical advice before pregnancy so the process can be monitored, and if treatment is necessary, it can be provided early.

The risk of heart disease in offspring varies, with some evidence suggesting that vitamin intake before and during early pregnancy may reduce risks.

Last updated on
Best viewed with Chrome 79.0, Edge 112.0, Firefox 61.0, Safari 11
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
  • NUHS Pharmacy
  • Yong Loo Lin School of Medicine
  • Faculty of Dentistry
  • Saw Swee Hock School of Public Health
Back to Top