A heart murmur is an extra, unusual sound in your heartbeat. Most heart murmurs are harmless. But they can be a sign of a problem with your heart. You might need treatment to keep your heart healthy.
Jump straight to:
- What is a heart murmur?
- What are the types of heart murmurs?
- What are the signs and symptoms of a heart murmur?
- I am worried about my heart murmur; can a heart murmur be dangerous?
- Innocent heart murmurs in children
- What causes a heart murmur?
- How is a heart murmur diagnosed?
- Will my heart murmur need treatment?
- Do you need support?
What is a heart murmur?
A heart murmur is an extra, unusual sound in your heartbeat. It can sound like a whooshing or swishing noise. The extra noise happens when your blood doesn’t flow smoothly through your heart.
Your doctor can hear the sounds your heart makes through a stethoscope. They will listen to the blood flowing through your heart, and your heart valves opening and closing.
Most heart murmurs are harmless. But if your doctor hears an extra, unusual sound, they might send you for tests to see how well your heart is working.
What are the types of heart murmurs?
There are three main types of heart murmurs:
- systolic murmur – when the heart is pumping blood to the rest of the body
- diastolic murmur – when the heart relaxes between beats to fill up with blood
- continuous murmur – throughout the heartbeat.
What are the signs and symptoms of a heart murmur?
Many people with a heart murmur don’t feel any symptoms. But a heart murmur can cause some symptoms like:
- fainting
- dizziness
- chest pain
- shortness of breath
- swelling in your legs, arms or tummy area
- a continuous cough that doesn’t seem to be getting better
- sweating a lot when you’re resting or doing minimal activity
- not growing at a normal rate and a lack of appetite (in babies and children only).
If you experience symptoms, visit your local GP. Your doctor can listen to your heart with a stethoscope and refer you to have tests or treatment with a specialist if needed. They can also support you if you feel worried or concerned.
You should call 999 immediately if you're experiencing:
- pain in your chest or upper body
- difficulty breathing or shortness of breath.
I am worried about my heart murmur; can a heart murmur be dangerous?
Most heart murmurs aren’t dangerous. But sometimes they can be a sign of a problem with your heart. Heart murmurs are classed as either:
- Innocent heart murmur – when your heart still beats normally but makes extra sounds when your blood flows through your heart faster than usual. Innocent murmurs are harmless.
Innocent heart murmurs are common in babies, young people and adults. They can come and go or happen regularly throughout your life.
- Abnormal heart murmur – when the extra sounds in your heartbeat are caused by a problem with your heart. This can be dangerous if it’s left untreated, but this is rare.
Abnormal heart murmurs are rare, especially in babies or young people. If your doctor thinks you might have an abnormal heart murmur, they will arrange tests to see how your heart is working. If your healthcare team diagnoses a problem with your heart, they will discuss treatment options with you. Your healthcare team will understand if you feel worried and can support you.
Innocent heart murmurs in children
It’s common for babies and children to experience ‘innocent’ heart murmurs. They usually disappear by the time they reach puberty (between the ages of 8-14) and don’t need any treatment.
Your child might have harmless murmurs come and go depending on their breathing, their heart rate and how active they’re being at the time.
What causes a heart murmur?
Innocent heart murmurs are caused by blood flowing through your heart faster than usual. This can be caused by:
- an overactive thyroid (a small butterfly-shaped gland in the neck)
- growing quickly (in babies and young people)
- untreated high blood pressure
- exercise or physical activity that raises your heart rate
- pregnancy (your body makes and pumps extra blood for your baby)
- having a fever (a raised temperature makes your heart pump blood faster)
- anaemia (when you don’t have enough healthy red blood cells to carry a normal amount of oxygen around your body).
Abnormal heart murmurs are caused by a problem with your heart. The problem could be:
- An infection – sometimes bad bacteria can infect your heart muscle and cause conditions like rheumatic fever.
- A congenital heart condition – structural problems with the heart which develop when a baby is in the womb.
- Heart valve disease – a problem with your heart valves could interrupt the normal blood flow.
How is a heart murmur diagnosed?
Your doctor will listen to your heart with a stethoscope to see if you have a heart murmur. If they think it could be an abnormal heart murmur, your healthcare team may arrange tests like:
- Chest x-ray – to see if your heart muscle looks bigger than it should be.
- ECG (electrocardiogram) - to check the rhythm, rate and electrical activity of your heart.
- Echocardiogram – an ultrasound of your heart to see if there’s a problem with the structure of your heart or your heart valves.
These tests are very common, but you can speak to your doctor if you feel worried about having them.
Are you finding it hard to get medical help?
We know thatmany of you are experiencing delays to treatment at this time, or have questions and concerns about getting medical help. We've created this set of information to help you with these issues.
- Where to get medical help if your appointment is delayed or cancelled
- Appointment and surgery delays
- When do you still need to get medical help?
- Making the most of phone and video appointments
Will my heart murmur need treatment?
Innocent heart murmurs don’t usually need treatment. But if your murmur is caused by a problem with your heart or another condition, then the cause of the murmur may need treatment.
There are many treatments for underlying heart conditions.
Your doctor will tell you if you need treatment. They will discuss the options, answer your questions and create a plan to treat and manage your heart murmur with you.
Treatments might be recommended to help you manage the symptoms of your heart murmur even if you don’t have an underlying heart condition.
Do you need support?
Having a heart murmur or an underlying problem with your heart can be worrying. Your local GP service and healthcare team are there to help you.
But if you’re feeling concerned and would like emotional support, our cardiac nurses can help you too. You can contact our Heart Helpline nurses by phone or email. Or you can connect with other people in a similar situation to you on our online HealthUnlocked community.
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Page last reviewed: March 2022
Next review due: March 2025
