Heart murmurs

A heart murmur is an extra or unusual sound heard while someone listens to your heart with a stethoscope. Instead of only the usual heartbeat sounds, blood flow may create a swishing or whooshing noise.

A murmur is a physical finding, not a disease. Many are innocent, meaning the heart is healthy and the sound comes from normal blood flow. Other murmurs may be linked to a heart valve problem, a condition present from birth, or another cause that changes how blood flows.

The sound alone cannot show whether there is a heart problem. Its timing, location, loudness, and your other symptoms help determine whether tests are needed.

You usually cannot feel a heart murmur. It is most often noticed during a routine examination, pregnancy appointment, childhood check-up, or assessment for another concern.

If the murmur is related to a heart condition, you may also notice:

• Shortness of breath during activity or while lying down
• Unusual tiredness or reduced ability to exercise
• Chest discomfort
• Dizziness or fainting
• A fast, pounding, or irregular heartbeat
• Swelling of the feet, ankles, or abdomen

Babies with an important heart problem may breathe quickly, sweat during feeds, feed poorly, gain weight slowly, or develop blue or grey lips or skin. These signs need prompt medical assessment.

These symptoms can have many causes other than a heart murmur or heart disease.

Common and usually harmless causes

Innocent murmurs are caused by blood moving normally through a healthy heart. They are common findings in children and may come and go as a child grows. Adults can also have harmless flow murmurs.

Blood may move faster during fever, pregnancy, exercise, or periods of strong emotion. This can make normal blood flow easier to hear. The murmur may fade when the temporary cause settles.

Heart valve causes

Valves act like one-way doors inside the heart. A murmur may occur if a valve is narrowed and blood has difficulty passing through, or if it does not close fully and blood leaks backward.

Valve changes may be present from birth or develop later because of ageing, previous infection, inflammation, or other heart conditions. A valve problem can be mild and stable, or it may need regular monitoring and treatment.

Less common causes

A murmur may be related to a structural difference present from birth, such as an opening between heart chambers. Anaemia, which means too few healthy red blood cells, and an overactive thyroid can also increase blood flow and produce a murmur.

Rarely, a new murmur with fever or feeling very unwell may be caused by infective endocarditis. This is an infection involving the heart's inner lining or valves and needs urgent assessment.

Call emergency services if you have a murmur or possible heart condition along with:

• Severe trouble breathing or breathlessness at rest
• Chest pain that is severe, persistent, or accompanied by sweating
• Fainting with ongoing weakness, confusion, or breathing difficulty
• Blue or grey lips, skin, or tongue
• Sudden facial weakness, arm weakness, or difficulty speaking

Seek same-day medical care for a newly identified murmur accompanied by fever, chills, rapidly worsening breathlessness, fainting, or a marked decline in how well you can function.

A baby needs urgent assessment for fast or difficult breathing, blue or grey colouring, extreme sleepiness, or difficulty feeding.

Book a routine appointment if a murmur has recently been found and no follow-up plan was given. You should also arrange review if a known murmur is accompanied by new fatigue, palpitations, ankle swelling, breathlessness, chest discomfort, or reduced exercise tolerance.

A clinician will ask about your symptoms, health history, medicines, family history, and any previous heart infection or procedure. They will listen to different areas of your chest and may check whether the sound changes with your position.

Features of the murmur can suggest whether it is likely to be innocent or needs further investigation. These include when it occurs during the heartbeat, where it is loudest, and whether the sound travels to the neck, back, or another part of the chest.

An echocardiogram, or heart ultrasound, is the main test used when a structural or valve problem is suspected. It shows the heart chambers, valves, pumping action, and direction of blood flow.

Depending on your situation, other tests may include an electrocardiogram to record the heart's electrical activity, blood tests, a chest X-ray, or heart rhythm monitoring. Not every murmur requires every test.

An innocent murmur does not usually need treatment. If fever, anaemia, thyroid disease, or another condition is increasing blood flow, treatment is directed at that cause.

Heart valve or structural conditions may be monitored with check-ups and repeat echocardiograms. Some people need medicines to manage related symptoms or reduce strain on the heart. More significant valve problems may require a procedure or surgery.

Keep planned follow-up appointments and tell your healthcare team if your symptoms change. Regular movement, not smoking, and managing blood pressure support general heart health, but they do not correct a narrowed or leaking valve.

Do not restrict exercise solely because a murmur was heard. Ask about safe activity if you have symptoms, a diagnosed heart condition, or specific exercise restrictions.

Most people with murmurs do not need antibiotics like amoxicillin or doxycycline before dental work. Antibiotics are recommended only for certain people at high risk of infective endocarditis. Maintain good dental care and follow the advice given for your specific heart history.

An innocent childhood murmur may become quieter or disappear as the child grows. A temporary flow murmur may settle when fever, pregnancy, anaemia, or another trigger resolves.

A murmur caused by a valve or structural change may remain for life. Some conditions stay mild for years, while others gradually change and need monitoring. The murmur's loudness does not always match the seriousness of the cause.

Your follow-up plan will depend on the underlying finding, your symptoms, and test results. Seek review earlier than planned if breathlessness, fainting, chest discomfort, swelling, or exercise tolerance worsens.

Can I hear my own heart murmur?

Usually not. A murmur is generally heard through a stethoscope. Sounds you notice in your chest or ears may have another explanation.

Does a murmur mean that I have heart disease?

No. Many murmurs are innocent. Others are signs of valve or structural changes, so the full examination and any recommended tests matter.

Can anxiety cause a murmur?

Anxiety can temporarily make the heart beat faster and increase blood flow, making a flow sound more noticeable. It does not usually cause a structural heart valve problem.

Can I exercise with a heart murmur?

Many people can exercise normally. Safe activity depends on whether the murmur is innocent or linked to a heart condition, and whether you have symptoms.

Will I need regular scans?

Not everyone does. Repeat echocardiograms may be advised when a valve or structural condition needs monitoring.