Hearing that your child has a heart murmur can naturally make you feel concerned, but it does not always mean there is a problem with their heart. A heart murmur is an extra sound heard through a stethoscope, and in many healthy children it is simply caused by normal blood flowing through the heart.
Once a heart murmur has been confidently confirmed as innocent, it does not normally require treatment, activity restrictions or routine cardiology follow-up. Your child’s age, symptoms, family history and complete cardiovascular examination will help the clinician decide whether reassurance is appropriate or further assessment is needed.
What Is a Heart Murmur?
A heart murmur is an extra sound that a doctor hears through a stethoscope while listening to your child’s heartbeat. It happens when blood flow becomes audible as it moves through the heart, and this can occur in a completely normal heart or because of a structural heart difference.
A murmur is a clinical finding rather than a diagnosis or illness. Some murmurs can be confidently identified as innocent after the history and examination, while others require further assessment. Parents cannot normally hear the murmur themselves because it is usually detected with a stethoscope during a routine examination or assessment for another concern.
How Does the Heart Create a Murmur?
Your child’s heart pumps blood through four chambers and four valves, and a heart murmur occurs when this blood flow creates an extra sound that can be heard through a stethoscope. This usually happens when the blood flows more quickly or becomes slightly turbulent as it moves through the heart or nearby blood vessels.
A murmur does not always mean there is a heart problem. Normal blood flow can sometimes be heard clearly through a stethoscope, particularly when a child’s heart is beating faster. The sound may also change or may not be heard at every examination because it can vary with breathing, movement and body position.
What Is the Difference Between an Innocent Murmur and One That Needs Further Assessment?
Not all heart murmurs indicate heart disease. A careful clinical assessment helps determine whether a murmur has innocent characteristics or needs further investigation.
- Innocent murmur: Caused by normal blood flow through a healthy heart and not associated with structural heart disease.
- Murmur needing further assessment: May be associated with a structural heart difference, valve condition or another change affecting blood flow.
- Clinical assessment: The clinician considers your child’s age, symptoms, oxygen saturation, pulses, heart sounds, growth and family history.
- Further referral: Specialist assessment or testing may be recommended when the murmur cannot be confidently classified as innocent.
Many childhood murmurs are innocent, but an appropriate assessment is important because some heart conditions may initially cause few or no noticeable symptoms.
Why Can an Innocent Murmur Become Louder?
An innocent heart murmur can become louder when your child’s heart is beating faster, such as during a fever, after exercise, while crying or when they feel anxious. These situations increase the speed of normal blood flow, which can make an innocent murmur easier to hear.
If a murmur is first heard during an illness, it may become quieter once your child recovers. A clinician should still assess its characteristics before deciding whether further investigation is needed.
What Can Cause an Abnormal Heart Murmur?
An abnormal heart murmur may be caused by a condition that changes the way blood flows through your child’s heart, such as a small opening between the heart chambers or a narrowed or leaking heart valve. Many of these conditions are present from birth, although they can vary from minor differences that only need monitoring to more complex problems requiring specialist care.
The sound of the murmur does not always reflect how serious the condition is, so your doctor will not rely on this alone. Even if your pregnancy scans were normal, some heart conditions may only become noticeable after birth, which is why your child’s symptoms and examination are equally important.
Can a Hole in the Heart Cause a Murmur?
A septal defect, sometimes described as a hole in the heart, can produce a murmur by changing blood flow between the heart’s chambers. Its significance depends on its type, size, location and effect on the heart. Some small ventricular septal defects become smaller or close as a child grows, while others require monitoring or treatment.
The term hole in the heart can sound worrying, but it covers several different conditions and does not always mean your child has a serious heart problem. Your child’s cardiologist will explain exactly what has been found, whether it is affecting your child’s heart function and if any treatment or follow-up is needed.
Can Heart Valves and Blood Vessels Cause Murmurs?
Yes, problems affecting your child’s heart valves or major blood vessels can sometimes cause a heart murmur by changing the way blood flows through the heart. A valve may be narrower than usual or may not close properly, while some blood vessel conditions can also create changes in blood flow that produce a murmur.
If your doctor suspects one of these conditions, they will examine your child carefully and may recommend tests such as an echocardiogram to look at the heart and blood vessels in more detail. The results will help explain the cause of the murmur and whether any treatment or ongoing monitoring is needed.
Do Children With Heart Murmurs Always Have Symptoms?
Many children with heart murmurs have no symptoms at all, especially when the murmur is innocent. Your child may feed, grow, play and stay active as expected, and the murmur is often discovered during a routine examination or while being seen for another reason.
Even when symptoms such as breathlessness, tiredness, chest discomfort or palpitations are present, they do not automatically mean the murmur is caused by a heart problem. Your doctor will consider your child’s symptoms, examination findings and medical history before deciding whether any further assessment is needed.
Which Symptoms May Appear in Babies?
A baby with an underlying heart condition may take longer to feed, need frequent pauses or become tired, sweaty or breathless during feeds. Other possible signs include rapid or laboured breathing, reduced feeding, poor weight gain and being less active than usual. These symptoms can have several causes, so your baby needs medical assessment rather than an assumption that the murmur is responsible.
Arrange prompt medical assessment if your baby develops feeding difficulties, breathlessness during feeds, unusual sleepiness, reduced activity or poor weight gain. Tell the healthcare professional that a heart murmur has previously been detected.
Call 999 if your baby’s 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 the fingers, toes, hands or feet appear blue or grey and your baby is otherwise responsive and breathing normally, contact NHS 111 for urgent advice.
Which Symptoms May Appear in Older Children?
If your child is older, they may tell you about symptoms such as breathlessness, unusual tiredness, dizziness, palpitations or chest discomfort. You might also notice that they struggle to keep up with friends or avoid activities they previously enjoyed.
Pay particular attention if these symptoms occur during exercise, especially if your child faints, experiences chest discomfort or feels their heart racing or fluttering. Keeping a note of when the symptoms started, what your child was doing and how long they lasted can provide helpful information for your doctor.
When Does a Heart Murmur Need Urgent Attention?
Call 999 if your child is not breathing, has severe difficulty 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.
Call 999 if their lips, tongue, face or skin suddenly turn blue or grey. On brown or black skin, check the palms, soles, lips, gums or inside the eyelids. If only the fingers, toes, hands or feet are blue or grey and your child is responsive and breathing normally, contact NHS 111.
Which Murmur Features May Prompt Further Assessment?
Clinicians consider when the murmur occurs during the heartbeat, how loud it is, its quality and location, and whether it spreads to another area of the chest, back or neck. Features that may require further assessment include a diastolic murmur, a continuous murmur that cannot be suppressed, a loud or harsh sound, an associated vibration known as a thrill, unusual heart sounds or radiation to the back or neck.
These findings require professional interpretation and cannot be assessed reliably from an online description or recording. The clinician will consider them alongside your child’s pulses, oxygen saturation, symptoms, growth and family history before deciding whether referral or testing is appropriate.
What Will the Doctor Ask and Examine?
Your doctor will ask about your child’s symptoms, including breathing difficulties, fainting, palpitations, chest discomfort, feeding problems and exercise tolerance, as well as their medical history, growth and any medicines they take. You should also mention any family history of heart conditions or sudden unexplained deaths, as this can help guide the assessment.
During the examination, your doctor may check your child’s pulse, blood pressure and oxygen saturation and listen carefully to their heart and lungs. If the murmur appears innocent and your child is otherwise healthy, no further tests may be needed, but any concerning findings may lead to a referral for specialist assessment.
Clinical Tip
Before the appointment, note 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 or unexplained sudden death at a young age.
Which Tests May Be Used to Diagnose the Cause?
If further assessment is needed, your child may have an ECG to record the heart’s electrical activity or an echocardiogram to examine its structure, movement and blood flow. Both are non-invasive and usually well tolerated, although removing ECG electrodes or pressure from the ultrasound probe may cause brief discomfort. An echocardiogram does not use ionising radiation.
Not every child with a murmur requires an ECG or echocardiogram. When the history and examination confidently indicate an innocent murmur in a healthy child, reassurance may be sufficient. Tests or specialist referral are more appropriate when symptoms, concerning murmur characteristics, abnormal examination findings or diagnostic uncertainty are present.
Evidence Note
Clinical examination remains central when a murmur is detected. UK referral guidance states that routine ECGs and chest X-rays do not significantly contribute to distinguishing an innocent murmur from structural heart disease in an otherwise well, asymptomatic child. An echocardiogram is not required when a trained clinician confidently identifies an innocent murmur, but referral or imaging may be appropriate when symptoms, concerning murmur features, abnormal examination findings or diagnostic uncertainty are present (Norfolk and Norwich University Hospitals NHS Foundation Trust, 2023; Ford, Lara and Park, 2022).
Why Are Newborn Heart Murmurs Assessed Carefully?
A newborn murmur 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 the normal circulatory changes that occur after birth, but they should not be assumed to be innocent solely because the baby appears well.
The assessment may include checking oxygen saturation, examining the femoral pulses and reviewing your baby’s breathing, feeding, colour and general wellbeing. Depending on the findings and the local neonatal pathway, your baby may need observation, an echocardiogram, urgent specialist discussion or planned outpatient follow-up.
UK Guidance Note
The NHS 20-week screening scan examines the baby’s heart but cannot identify every congenital heart condition. A murmur or concerning symptom after birth therefore still requires assessment according to the baby’s examination, oxygen saturation, pulses, feeding and general condition, even when antenatal scans were reported as normal.
How Are Innocent Heart Murmurs Treated?
An innocent heart murmur does not need treatment because your child’s heart is structurally normal. Once the murmur has been confirmed as innocent, your child can usually enjoy school, sport and other everyday activities without restrictions.
You may notice that the murmur sounds louder when your child is unwell, anxious or physically active, but this does not mean their heart has been damaged. In many children, innocent murmurs become quieter or disappear as they grow, and routine cardiology follow-up is not usually needed unless new symptoms develop.
Myth vs Fact
| Myth | Fact |
| Every heart murmur means that your child has heart disease. | Many childhood murmurs are innocent sounds produced by normal blood flow through a healthy heart. A clinician must assess the murmur before confirming that it is innocent. |
| A louder murmur always indicates a more serious condition. | The volume of a murmur does not reliably show how serious the underlying cause is. The full examination and any appropriate tests provide more useful information. |
| Every child with a murmur needs an echocardiogram. | A clearly innocent murmur in a healthy, symptom-free child may not require a heart scan or cardiology referral. |
| An innocent murmur prevents your child from playing sport. | Once the murmur has been confirmed as innocent, your child can normally exercise and participate in ordinary activities without restrictions. |
| A normal pregnancy scan rules out every congenital heart condition. | Antenatal scans identify many important conditions, but some heart differences are not visible before birth. |
| A heart murmur must be treated with medicine. | Treatment is only needed when there is an underlying condition requiring management. Innocent murmurs need no medicine. |
| If your child has no symptoms, an abnormal murmur is impossible. | Some structural heart differences cause few or no noticeable symptoms and are first detected when a murmur is heard. |
Key Takeaways
- A heart murmur is an additional sound, not a diagnosis by itself.
- Many childhood murmurs are innocent and occur in otherwise healthy hearts.
- A confirmed innocent murmur does not normally require treatment, activity restrictions or routine cardiology follow-up.
- Symptoms, family history and the complete cardiovascular examination help determine whether further assessment is needed.
- Not every child with a murmur needs an ECG or echocardiogram.
- Newborn murmurs require careful assessment because signs of congenital heart disease may initially be subtle.
- Call 999 if your child has severe breathing difficulty, suddenly develops blue or grey lips, tongue, face or skin, does not fully recover after fainting, or faints during exercise or while lying down.
FAQs
1. Can a heart murmur disappear as my child gets older?
Yes. Many innocent heart murmurs become quieter or disappear as a child grows and their circulation changes. Even if the murmur remains audible, a confirmed innocent murmur is not associated with structural heart disease and does not normally require treatment or activity restrictions.
2. Can a child be born with a heart murmur?
Yes. A murmur may be detected during the newborn examination. Some are temporary sounds associated with changes in circulation after birth, while others may indicate a congenital heart condition. Every newborn murmur should be assessed using the baby’s examination, oxygen saturation, pulses, feeding and general wellbeing.
3. Can illness make a heart murmur easier to hear?
Yes. Fever, anxiety, crying and exercise can increase blood flow and heart rate, making an innocent murmur more noticeable. The murmur often becomes quieter once your child has recovered.
4. Does every child with a heart murmur need to see a paediatric cardiologist?
Not every healthy older child with a clearly innocent murmur needs specialist referral. Paediatric cardiology assessment is more likely to be recommended when the murmur cannot confidently be classified as innocent, symptoms are present, another examination finding is abnormal or there is a concerning family history.
5. Are heart murmurs hereditary?
Most innocent heart murmurs are not inherited. However, some congenital and inherited heart conditions can run in families, so it is important to tell your doctor about any family history of congenital heart disease, cardiomyopathy, inherited rhythm disorders or sudden unexplained death.
6. Can my child receive vaccinations if they have a heart murmur?
A confirmed innocent murmur is not a reason to delay routine childhood vaccinations. If your child has a diagnosed heart condition, follow the individual vaccination advice provided by their GP, paediatrician or cardiology team, particularly if they take immune-modifying medicine or are due to undergo a specialist procedure.
7. Can a heart murmur come and go?
Yes. Innocent murmurs often vary in intensity and may only be heard during certain illnesses, after exercise or in particular body positions. This does not necessarily indicate a change in your child’s heart health.
8. Should I limit my child’s physical activity if they have a heart murmur?
Not unless advised by a healthcare professional. Children with a confirmed innocent murmur can usually take part in sports, physical education and normal daily activities without restrictions.
9. Can parents hear or feel their child’s heart murmur?
Usually not. A heart murmur is normally detected by a healthcare professional using a stethoscope. You may be able to feel your child’s heartbeat, but this does not allow you to determine whether a murmur is present or whether it is innocent.
10. What questions should I ask during a cardiology appointment?
You may wish to ask whether the murmur appears innocent or abnormal, whether further tests are needed, if your child can continue normal activities, whether follow-up is required, and what symptoms should prompt urgent medical review.
Final Thoughts: Understanding Heart Murmurs in Children
Learning that your child has a heart murmur can feel worrying, but a murmur is a clinical finding rather than a diagnosis. Many childhood murmurs are innocent and need no treatment or activity restrictions once they have been properly assessed. Symptoms, family history and the complete examination help determine whether reassurance, testing or follow-up is appropriate.
If your child has been advised to have a specialist assessment, you can arrange a consultation with a paediatric cardiologist experienced in assessing heart murmurs in children. Seek emergency help rather than waiting for an appointment if your child develops severe breathing difficulty, sudden blue or grey discolouration, collapse, reduced responsiveness or fainting during exercise.
References:
- Norfolk and Norwich University Hospitals NHS Foundation Trust (2023) ‘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 (2026) Echocardiogram. Available at: https://www.nhs.uk/tests-and-treatments/echocardiogram/
- 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
- 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/
- Royal Brompton and Harefield hospitals (no date) ‘Innocent heart murmur in children’. Available at: https://www.rbht.nhs.uk/our-services/innocent-heart-murmur-children