Hearing that your child has a heart murmur can feel worrying, especially if you are concerned that it may indicate a hidden heart problem. However, many murmurs found in otherwise healthy children are innocent sounds caused by normal blood flow through a healthy heart. Once a murmur has been confidently confirmed as innocent, it does not normally require treatment or activity restrictions.
A heart murmur describes an extra sound rather than a specific diagnosis, so it does not automatically mean your child has heart disease. Your doctor will consider your child’s age, symptoms, growth, examination findings and family history to decide whether the murmur has innocent characteristics or whether further assessment is needed.
What Does a Heart Murmur Mean?
A heart murmur is an extra sound that your child’s doctor hears when listening to their heart with a stethoscope. It may sound like a soft swish, hum, whoosh or vibration, and it happens when blood moves through the heart or nearby blood vessels.
A murmur is a clinical finding rather than a condition on its own, so it does not always mean there is a heart problem. Your doctor will look at the sound alongside your child’s symptoms, examination findings and medical history to understand what it means, and you would not usually be able to hear or feel the murmur yourself.
What Is an Innocent Heart Murmur?
An innocent heart murmur is a sound produced by normal blood flow through a structurally healthy heart. It may also be called a functional, physiological or flow murmur. Children with an innocent murmur are usually well, growing normally and able to participate in everyday activities without restrictions.
The sound may change with your child’s position, breathing or heart rate and can become easier to hear during fever, crying, anxiety or exercise. Once a trained clinician has confirmed that the murmur is innocent, treatment and routine cardiology monitoring are not normally needed.
When Can a Heart Murmur Indicate an Underlying Condition?
A murmur may require further assessment when it is associated with a structural difference affecting the heart, valves or major blood vessels. Possible causes include an opening between heart chambers, a narrowed or leaking valve or an abnormal connection affecting blood flow.
The significance depends on the underlying diagnosis rather than the murmur alone. Some conditions need only monitoring, while others may require medicine, a catheter-based procedure or surgery. The murmur’s loudness does not reliably show how serious the condition is.
How Do Doctors Decide Whether a Murmur Is Innocent?
Your doctor will assess several features of the murmur, including when it occurs during the heartbeat, how long it lasts, where it is heard and whether it spreads to other areas. They may also listen while your child is lying down, sitting or standing, as an innocent murmur can change with position.
No single murmur characteristic should be interpreted in isolation. Your doctor will also consider your child’s symptoms, growth, oxygen saturation, blood pressure, pulses and family history. If the murmur does not clearly have innocent features, or if another part of the assessment raises concern, further tests or referral to a specialist may be recommended.
Which Murmur Characteristics May Need Further Investigation?
Clinicians assess when the murmur occurs during the heartbeat, how loud it is, its quality and location and whether it spreads to the neck, back or another area of the chest. Features that may prompt further assessment include a diastolic murmur, a continuous murmur that cannot be suppressed, a loud or harsh systolic murmur, a vibration felt on the chest wall, known as a thrill, unusual heart sounds or radiation to other areas.
These features require professional interpretation and cannot reliably be assessed using an online description or recording. The clinician will consider them alongside your child’s symptoms, pulses, oxygen saturation, blood pressure, growth and family history before deciding whether specialist assessment is appropriate.
Myth vs Fact
| Myth | Fact |
| Every heart murmur in a child is serious. | Many murmurs heard in healthy, symptom-free children are innocent and are not caused by heart disease. A trained clinician must assess the murmur before confirming that it is innocent. |
| A loud murmur always means that the heart problem is severe. | Murmur volume does not reliably show how serious an underlying condition is. Doctors consider the full examination and any appropriate test results. |
| A child with a heart condition will always have obvious symptoms. | Some children with structural heart differences appear well, and the murmur may be the first sign that further assessment is needed. |
| Every murmur requires an echocardiogram. | A typical innocent murmur in a healthy child may be diagnosed clinically without a heart scan. |
| An innocent murmur prevents a child from exercising. | A confirmed innocent murmur does not normally require restrictions on sport, physical education or everyday activity. |
| A normal pregnancy scan rules out every heart condition. | Antenatal scans identify many important abnormalities but cannot detect every congenital heart difference. |
| A murmur that becomes louder during a fever is becoming more dangerous. | Fever increases the heart rate and can make an innocent murmur easier to hear without changing the structure of the heart. |
Can a Child With a Heart Condition Have No Symptoms?
Some children with a heart condition may have symptoms, but others can appear completely well, with a murmur being the first sign that further assessment is needed. Small structural differences may not cause noticeable problems but can still create a sound that your doctor can hear.
The absence of symptoms does not automatically mean that a murmur is innocent, and symptoms do not always mean there is a heart problem. Your doctor will consider the murmur’s features, your child’s overall health and any symptoms to decide whether they are connected or whether another cause is more likely.
Which Symptoms Are Important in Babies?
A baby with an underlying heart condition may take longer to feed, require frequent pauses or become tired, sweaty or breathless during feeds. Other possible signs include rapid or laboured breathing, reduced feeding, poor weight gain, unusual sleepiness or being less active than normal. These symptoms have several possible causes, so your baby needs medical assessment rather than an assumption that the murmur is responsible.
Call 999 if your baby is not breathing, has severe difficulty breathing, becomes limp or unresponsive, or if their lips, tongue, face or skin suddenly turn blue or grey. On brown or black skin, this may be easier to see on the palms, soles, lips, gums or inside the eyelids. If only your baby’s fingers, toes, hands or feet appear blue or grey and they are otherwise responsive and breathing normally, contact NHS 111 for urgent advice.
Which Symptoms Matter in Older Children?
Older children may be able to tell you about symptoms such as chest discomfort, dizziness, palpitations, breathlessness or unusual tiredness. You may also notice that your child struggles to keep up with friends, avoids activities or finds exercise more difficult than before.
Request prompt medical assessment if your child develops chest discomfort, palpitations, unusual breathlessness, dizziness or reduced exercise tolerance, particularly when the symptoms occur during physical activity or there is a relevant family history.
Call 999 if your child is not breathing, cannot be woken within one minute after fainting, has not fully recovered or has difficulty speaking or moving. Also call 999 if they faint during exercise or while lying down, faint with chest pain or a pounding, fluttering or irregular heartbeat, are shaking or jerking because of a suspected seizure or fit, or have seriously injured themselves.
If your child recovers fully and emergency help is not needed, note what happened, how long the episode lasted and how they recovered, and arrange medical assessment to help identify the cause.
When Is Blue or Grey Colouring an Emergency?
Blue or grey colouring of your child’s lips, tongue, face or skin may indicate low oxygen levels or another serious medical problem. On brown or black skin, the change may be easier to see on the lips, gums, palms of the hands, soles of the feet or inside the eyelids.
Call 999 if your child’s lips, tongue, face or skin suddenly turn blue or grey. They may also have difficulty breathing, chest pain, confusion, drowsiness or dizziness, or appear limp, floppy or unresponsive. If only their fingers, toes, hands or feet appear blue or grey and they are otherwise responsive and breathing normally, contact NHS 111 for urgent advice.
Why Are Murmurs in Newborn Babies Assessed Carefully?
A murmur in a newborn baby requires careful paediatric assessment because signs of congenital heart disease can be subtle during the first days of life. Many newborn murmurs are temporary or related to normal changes in the circulation after birth, but they should not be assumed to be innocent solely because the baby initially appears well.
The assessment may include oxygen-saturation measurements, examination of the femoral pulses and checks of breathing, feeding, colour and general wellbeing. Abnormal oxygen levels, weak or absent femoral pulses or signs of heart failure or shock require urgent investigation and specialist discussion.
UK Guidance Note
The 2025 North West, North Wales and Isle of Man Congenital Heart Disease Operational Delivery Network guideline advises recording blood pressure, ECG findings and oxygen saturation, where available, before cardiac review, including pre- and post-ductal oxygen saturation in neonates. Respiratory distress, poor peripheral pulses, central cyanosis or other signs of heart failure require urgent specialist discussion, while feeding difficulty, failure to thrive and age under six months support earlier assessment.
Whether echocardiography is needed immediately, before discharge or through a planned outpatient pathway will depend on the baby’s clinical condition and the local neonatal protocol.
Does a Normal Pregnancy Scan Rule Out Every Heart Condition?
A normal 20-week pregnancy scan can identify many important structural heart conditions, but it cannot detect every congenital heart difference. Some conditions are difficult to see before birth or may become more apparent only after the baby’s circulation changes following delivery.
A reassuring antenatal scan is helpful, but a murmur or concerning symptom after birth still needs to be assessed according to the baby’s examination, oxygen saturation, pulses, feeding and general condition.
Why Does Family History Matter?
Family history can provide important clues because some heart conditions may run in families. Your doctor may ask about relatives with congenital heart disease, heart muscle conditions, abnormal heart rhythms, aortic problems, pacemakers, defibrillators or sudden unexplained deaths at a young age.
Having a family history does not mean your child has inherited a heart condition, but it may mean your doctor recommends further assessment sooner. Try to share any details you know about relatives’ diagnoses and ages, especially if your child also has symptoms such as fainting, palpitations or problems during exercise.
Clinical Tip
Before the appointment, record when your child’s symptoms occur, what they were doing, how long the episode lasted and how they recovered. Bring an up-to-date list of your child’s medicines and details of any family history of congenital heart disease, cardiomyopathy, inherited heart-rhythm conditions, aortic disease or unexplained sudden death at a young age.
What Happens During the Medical Assessment?
During the medical assessment, your doctor will ask about when the murmur was found and whether your child has experienced symptoms such as feeding difficulties, breathing problems, tiredness, palpitations, chest discomfort or fainting. They may also ask about pregnancy, birth, previous illnesses, medicines and family history to understand the full picture.
The examination usually includes listening to your child’s heart and lungs, checking their pulses, oxygen saturation and blood pressure, and comparing pulses in the arms and legs. These findings help your doctor decide whether your child needs reassurance, follow-up monitoring or referral to a paediatric cardiologist.
Does Every Child With a Murmur Need Heart Tests?
Not every child with a heart murmur needs tests such as an ECG or echocardiogram. If your doctor identifies a typical innocent murmur in a healthy child with no symptoms and a normal examination, they may feel that further investigations are not needed.
Further tests are more likely if the murmur has unusual features, your child has symptoms or there is any uncertainty about the cause. Your doctor will explain why they recommend reassurance, monitoring or specialist assessment, and what signs you should look out for before any follow-up.
Evidence Note
Clinical assessment is central when a murmur is detected. UK guidance states that routine ECGs and chest X-rays add little when distinguishing an innocent murmur from structural heart disease in a well, asymptomatic older child. Echocardiography may not be necessary when a trained clinician confidently identifies an innocent murmur, but referral or imaging is appropriate if symptoms, concerning murmur features, abnormal findings or uncertainty are present (Norfolk and Norwich University Hospitals NHS Foundation Trust, 2024; Ford, Lara and Park, 2022).
Which Heart Tests May Be Recommended?
An ECG and echocardiogram are two common tests used to understand how your child’s heart is working. These non-invasive investigations provide detailed information without using radiation.
- ECG test: Records the heart’s electrical activity and rhythm.
- Echocardiogram: Uses ultrasound to assess heart structure, valves, movement and blood flow.
- Safe procedures: Neither test uses ionising radiation, and both are generally well tolerated.
- Brief discomfort: ECG stickers or mild pressure from the ultrasound probe may cause temporary discomfort.
- Further tests: Additional investigations are only recommended if initial findings suggest they may be helpful.
These tests help the cardiologist understand your child’s heart health and decide whether any further assessment is needed. The choice of investigations depends on your child’s symptoms, examination and initial results.
What Happens If the Murmur Is Innocent?
If your child’s murmur is confirmed as innocent, they do not need treatment because their heart is healthy and the sound does not affect the heart or circulation. Your child can usually continue with everyday activities, including school, swimming, physical education and sport, without any special restrictions.
The murmur may still be heard at future appointments or become louder when your child has a fever, feels anxious or their heart rate increases. Routine cardiology follow-up is not usually needed once the diagnosis is confirmed, but you should seek medical advice if new symptoms such as fainting, breathlessness, persistent palpitations or reduced exercise tolerance develop.
What Happens If an Underlying Condition Is Found?
If your child is found to have a structural heart difference, it does not always mean they will need an operation. Some conditions are mild and only require monitoring, while others may need medicine, catheter-based treatment or surgery depending on how they affect the heart.
Your child’s cardiologist will explain the diagnosis, possible treatment options and what to expect in the future. Regular follow-up may be recommended to check your child’s growth, symptoms and heart function, helping ensure the right care is provided at the right time.
Key Takeaways
- A heart murmur is an additional sound rather than a diagnosis.
- Many murmurs in otherwise healthy children are innocent and are caused by normal blood flow.
- A confirmed innocent murmur does not normally require medicine, activity restrictions or routine cardiology follow-up.
- Some children with underlying heart conditions have few or no obvious symptoms.
- Newborn murmurs require careful assessment because warning signs may initially be subtle.
- Not every child with a murmur requires an ECG or echocardiogram.
- Call 999 if your child has severe breathing difficulty, suddenly develops blue or grey lips, tongue, face or skin, cannot be woken or does not fully recover after fainting, or faints during exercise or while lying down.
FAQs
1. At what age are heart murmurs most commonly detected in children?
Heart murmurs can be detected at any age, including during the newborn examination, infancy or later childhood. Many innocent murmurs are first noticed during routine health checks or while a child is being examined for another illness.
2. Can a heart murmur develop later in childhood?
Yes. Although some murmurs are present from birth, innocent murmurs can become noticeable later in childhood as blood flow changes or during periods of illness, growth or increased heart rate.
3. Does a heart murmur always mean my child has congenital heart disease?
No. Many childhood heart murmurs are innocent and occur without structural heart disease. A smaller proportion are associated with congenital heart disease or another condition affecting the heart or blood flow, which is why the complete clinical assessment is important.
4. Can my child attend school if they have a heart murmur?
In most cases, yes. Children with an innocent heart murmur can attend school, participate in normal activities and enjoy physical education unless a healthcare professional advises otherwise.
5. Will my child need regular heart check-ups for an innocent murmur?
Usually not. Once a healthcare professional has confirmed that the murmur is innocent, routine cardiology follow-up is generally unnecessary unless new symptoms develop or examination findings change.
6. Does every child with a heart murmur need an echocardiogram?
No. A trained clinician may be able to identify a typical innocent murmur in an otherwise healthy child from the medical history and examination. An echocardiogram is more likely to be recommended when the murmur has concerning features, your child has symptoms or other abnormal findings are present, or the diagnosis remains uncertain.
7. Should I tell other healthcare professionals that my child has a heart murmur?
Yes. It is helpful to mention your child’s history during future medical appointments. If the murmur has already been confirmed as innocent, you can also let clinicians know that it has previously been assessed.
8. Can heart murmurs affect my child’s growth and development?
An innocent heart murmur does not affect growth, learning or development. If a structural heart condition is present, growth may be affected in some cases, which is why appropriate medical assessment is important.
9. Can a child with a heart murmur safely have surgery or a general anaesthetic?
Tell the surgical and anaesthetic teams about your child’s murmur and provide details of any previous cardiac assessment or test results. Every child should receive an appropriate pre-operative assessment before an anaesthetic.
If the murmur has not been assessed, your child has relevant symptoms or an underlying heart condition has been diagnosed, the anaesthetic team may request further information, test results or specialist assessment before deciding how to proceed.
10. When should I seek another medical review after an innocent heart murmur has been diagnosed?
Arrange a medical review if your child develops new symptoms such as breathlessness, fainting, chest pain during exercise, persistent palpitations, poor growth, reduced exercise tolerance or if another healthcare professional identifies new concerns during examination.
Final Thoughts: Understanding Your Child’s Heart Murmur
Most heart murmurs in children are not serious and are often caused by normal blood flow through a healthy heart. However, a proper assessment is important because a murmur can occasionally be linked to an underlying heart condition that may need monitoring or treatment. Looking at your child’s symptoms, examination findings, family history and any recommended tests helps doctors understand the cause of the murmur and decide the most appropriate next steps.
If you are concerned about heart murmurs in children, you can get in touch with London Paediatric Clinic. Our paediatric cardiology team provides specialist assessments to help determine whether a murmur is innocent or whether further investigations, advice or ongoing care may be needed for your child.
References:
- North West, North Wales and Isle of Man Congenital Heart Disease Operational Delivery Network (2025) Paediatric Cardiology Outpatient Referral Guideline. Available at: https://www.northwestchdnetwork.nhs.uk/wp-content/uploads/2025/08/NWCHDN_21_Paediatric_Cardiology_Outpatient_Referral_Guideline_Final_11.08.25.pdf
- Norfolk and Norwich University Hospitals NHS Foundation Trust (2024) Cardiology Advice and Referral Pathways Paediatrics. CA4073 v7.
- Available at: https://www.nnuh.nhs.uk/publication/download/cardiology-advice-and-referral-pathways-paediatrics-ca4073-v7/
- Leeds Teaching Hospitals NHS Trust (2025) Heart murmur in newborn babies – What it means, what to look out for and what happens next. Available at: https://www.leedsth.nhs.uk/patients/resources/heart-murmur-in-newborn-babies-2/
- NHS (2025) Congenital heart disease. Available at: https://www.nhs.uk/conditions/congenital-heart-disease/
- NHS (2023) Blue or grey skin or lips (cyanosis). Available at: https://www.nhs.uk/symptoms/blue-skin-or-lips-cyanosis/
- NHS (2024) 20-week screening scan. Available at: https://www.nhs.uk/pregnancy/your-pregnancy-care/20-week-scan/
- NHS (2023) Electrocardiogram (ECG). Available at: https://www.nhs.uk/tests-and-treatments/electrocardiogram/
- NHS (2026) Echocardiogram. Available at: https://www.nhs.uk/tests-and-treatments/echocardiogram/
- Ford, B., Lara, S. and Park, J. (2022) Heart murmurs in children: evaluation and management. American Family Physician, 105(3), pp. 250–261. Available at: https://pubmed.ncbi.nlm.nih.gov/35289571/
- NHS (2023) ‘Fainting’. Available at: https://www.nhs.uk/symptoms/fainting/
- Kingston and Richmond NHS Foundation Trust (2024) ‘Syncope (fainting) in children and young people’. Available at: https://www.kingstonandrichmond.nhs.uk/patients-and-families/patient-leaflets/syncope-fainting-children-and-young-people