Heart Murmur
Heart Murmur: A Complete Patient Guide
A heart murmur is an extra or unusual sound heard between heartbeats through a stethoscope, caused by turbulent blood flow in or near the heart. It is not a disease in itself but a sign. Many murmurs are innocent (functional) and harmless, particularly in children, young adults and in pregnancy. Others point to a problem with a heart valve or a structural abnormality that needs assessment.
Murmurs are described by when they occur in the heartbeat (systolic, diastolic or continuous), their loudness (graded 1 to 6), where they are heard best and how they change with posture or breathing. Diastolic murmurs, loud or long murmurs, and murmurs with symptoms are more likely to be significant.
The most common valve conditions found in adults are aortic stenosis, mitral regurgitation, aortic regurgitation and mitral valve prolapse. An echocardiogram is the key test: it shows whether the heart and valves are normal, and when a murmur is innocent it gives reassurance without further follow-up. The 2021 ESC/EACTS guidelines on valvular heart disease set out when and how valve disease should be followed and treated.
Innocent murmurs cause no symptoms. Murmurs from valve or heart disease may, but not always, produce symptoms.
Innocent murmurs
No symptoms; the murmur is found at a routine check or when you are unwell with a fever, anaemia or pregnancy
Often soft, short, vary with position and are heard in children and young adults
Symptoms that may point to valve disease
Breathlessness on exertion or lying flat
Chest tightness or pain on exertion
Fatigue, reduced exercise tolerance
Palpitations, dizziness or fainting (especially on exertion)
Ankle swelling
Signs your doctor may find
A murmur that is loud, harsh, diastolic or accompanied by a thrill (a vibration felt over the heart), abnormal heart sounds, or signs of heart failure.
Murmurs are caused by turbulent blood flow, which arises in several ways.
Innocent or functional causes
Normal blood flow in a healthy heart, especially in children and thin young people
Increased flow with fever, anaemia, overactive thyroid, pregnancy or exercise
Valve disease
Aortic stenosis: a narrowed aortic valve, often from age-related calcification or a bicuspid valve
Mitral regurgitation: a leaking mitral valve, which may result from prolapse or a dilated heart
Aortic regurgitation and mitral stenosis (the latter often follows rheumatic fever)
Tricuspid and pulmonary valve disease, and infected or damaged valves (endocarditis)
Other structural causes
Holes in the heart: ventricular septal defect, atrial septal defect
Hypertrophic cardiomyopathy and other congenital conditions
Previous valve surgery or prosthetic valves
The aim is to decide whether the murmur is innocent or due to disease, and if disease, how severe.
1. Examination
An experienced clinician listens carefully to the timing, quality and loudness of the murmur, and notes how it changes with posture, breathing and manoeuvres, together with pulse, blood pressure and signs of heart failure.
2. ECG
An ECG looks for rhythm problems, thickening of the heart and signs of valve disease.
3. Echocardiogram
An echocardiogram is the key test. It shows valve structure and movement, measures the severity of narrowing or leakage with Doppler, and assesses the size and function of the heart. The ESC recommends echocardiography for symptomatic patients and for murmurs that are diastolic, loud or suggestive of valve disease.
4. Further tests
Stress echo or exercise testing can show how a valve behaves with exertion, particularly when symptoms and severity do not agree. Cardiac MRI or CT may be used to assess complex valve or structural disease, and transoesophageal echo can provide detailed valve views.
5. Bubble echo for suspected holes
A bubble echo can look for a hole such as a patent foramen ovale or atrial septal defect when indicated.
Treatment depends on what is found.
Innocent murmurs
No treatment or follow-up is needed once an echocardiogram has confirmed a normal heart. Reassurance is the treatment.
Mild valve disease
Regular surveillance with clinical review and periodic echocardiography, with good blood pressure control and a healthy lifestyle.
Significant valve disease
Medicines can relieve symptoms (such as diuretics) and treat blood pressure, rhythm or heart failure, but do not repair the valve
Valve intervention is recommended when disease is severe and symptomatic, or when the heart is affected. It includes valve repair, valve replacement by surgery, or catheter-based approaches such as TAVI for aortic stenosis and transcatheter mitral procedures
Timing is important: intervention before the heart is damaged gives better long-term results
Preventing infection of the valves
Good dental hygiene and regular dental review are the most important measures. Routine antibiotics before dental work are no longer recommended for most people, but are advised for those with prosthetic valves or previous endocarditis.
Attend your reviews and echo appointments if you have valve disease, because timely treatment improves outcomes.
Report new symptoms such as breathlessness, chest tightness, palpitations, dizziness or fainting.
Look after your teeth and see a dentist regularly.
Stay active. Most people with mild valve disease can exercise normally. Ask for individual advice if the valve disease is moderate or severe.
Pregnancy: women with valve disease should seek advice before pregnancy.
Control other risks such as blood pressure, cholesterol and smoking.
Support is available from the British Heart Foundation, the NHS and Heart Valve Voice.
An innocent murmur has an entirely normal outlook and does not need treatment or follow-up.
Mild valve disease is often stable for years, and many people never need an operation.
Moderate and severe valve disease can progress, so regular monitoring identifies the right time to act.
When treated at the right time, valve repair and replacement give excellent results and restore life expectancy close to normal in many people.
The outlook depends on the type and severity of valve disease, heart function and other conditions.
A murmur is a reason to have your heart checked, at least once, with an echocardiogram if there is any doubt.
Arrange an assessment if you have:
A murmur found by a doctor, particularly in an adult, or one not previously investigated
Breathlessness, chest tightness, palpitations, dizziness or fainting
A murmur and a family history of heart valve disease, cardiomyopathy or sudden death
A known valve condition with a change in symptoms or overdue for review
A murmur found in pregnancy or before planning pregnancy
Usually reassuring if:
The murmur is soft, short, found in a child or young person without symptoms, and an echocardiogram is normal.
These features suggest significant heart disease and need prompt assessment, ideally within days.
Red flags
A murmur with breathlessness, chest pain or fainting on exertion
A loud, harsh murmur, a diastolic murmur or a thrill
Ankle swelling or breathlessness lying flat
A new murmur with fever or recent dental work or an IV line (possible endocarditis)
A murmur in an infant who is feeding poorly, breathing fast or growing slowly
What to do
Arrange an urgent consultation with an ECG and echocardiogram.
A murmur with the following needs emergency help.
Call 999 immediately if you have:
Chest pain or pressure lasting more than 15 minutes
Fainting or collapse, particularly on exertion
Severe breathlessness at rest, or pink frothy phlegm
Signs of a stroke: face drooping, arm weakness, slurred speech
Fever with a known valve problem
A persistent fever with a known valve condition or prosthetic valve needs same-day medical assessment, because endocarditis must be excluded.
A heart murmur is an extra sound caused by turbulent blood flow, and a sign, not a disease.
Many murmurs are innocent, especially in children, young adults and pregnancy.
Others are due to valve disease such as aortic stenosis or mitral regurgitation, or holes in the heart.
An echocardiogram is the key test and usually provides a clear answer.
Breathlessness, chest pain or fainting with a murmur need prompt assessment.
Innocent murmurs need no treatment or follow-up.
Valve disease is monitored, and repaired or replaced at the right time.
Good dental hygiene helps to prevent valve infection.
Guidelines and sources
This page follows current UK and European guidance:
NICE NG208: Heart valve disease presenting in adults: investigation and management.
Vahanian A et al. 2021 ESC/EACTS Guidelines for the management of valvular heart disease. European Heart Journal 2022;43:561-632.
These are the questions patients most often ask about heart murmurs.
What is a heart murmur?
An extra sound heard through a stethoscope between heartbeats, caused by turbulent blood flow. It is a sign and not a disease, and many are harmless.
Is a heart murmur serious?
Often not. Innocent murmurs are harmless. A murmur from a diseased valve may be significant, which is why an echocardiogram is often recommended.
What causes a heart murmur?
Normal fast blood flow (innocent), fever, anaemia, pregnancy and thyroid overactivity, or valve disease such as aortic stenosis or leaking valves, and holes in the heart.
What are the symptoms of a heart murmur?
Innocent murmurs cause none. Murmurs from valve disease may cause breathlessness, tiredness, chest tightness, palpitations, dizziness or fainting.
How is a heart murmur diagnosed?
By listening with a stethoscope, then an ECG and an echocardiogram, which shows the valves and measures severity.
Can a heart murmur go away?
Innocent murmurs often disappear with age or when the trigger, such as fever or pregnancy, passes. Murmurs from valve disease do not go away without treatment.
Do I need an echocardiogram for a heart murmur?
If it is in an adult, causes symptoms, is loud or diastolic, or you are unsure whether it is innocent, an echocardiogram is recommended. It confirms or excludes valve disease.
Can I exercise with a heart murmur?
Yes, if it is innocent or the valve disease is mild. With moderate or severe valve disease, you should have personal advice first.
Do I need antibiotics before dental work?
Not usually. Antibiotic prophylaxis is advised for people with prosthetic valves or a history of infective endocarditis, and good dental care matters for everyone with valve disease.
Can I have a private echocardiogram for a heart murmur?
Yes. A telephone, video or face-to-face consultation in Peterborough or Corby can review your murmur, and a private echocardiogram is available to see whether it is innocent or due to valve disease.
- Is my murmur innocent or due to a valve problem?
- Do I need an echocardiogram or other tests?
- If I have valve disease, how severe is it?
- How often should I be monitored?
- When might I need valve surgery or TAVI?
- Is it safe to exercise or become pregnant?
- Do I need antibiotics before dental procedures?
- What symptoms should make me seek help?
- Could the murmur be due to anaemia, pregnancy, fever or an overactive thyroid?
- Will my murmur change over time, and what would prompt a repeat scan?
Normal and abnormal blood flow
Normal valves: open fully and close tightly, so blood flows smoothly and quietly.
Stenosis: a narrowed valve forces blood through a small opening, creating turbulence and a murmur.
Regurgitation: a leaking valve allows blood to flow backwards, creating a murmur.
Innocent murmur: fast, healthy flow in a normal heart produces a soft sound.
If you have been told you have a heart murmur, or have breathlessness, chest tightness or dizziness, you may benefit from a telephone consultation or video consultation to discuss your symptoms in detail, or a face-to-face consultation in Peterborough or Corby for a more comprehensive assessment.
Investigations such as echocardiography, ECG reporting and stress echo may be recommended.
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Medically reviewed by Dr Salam Salloum, Consultant Cardiologist. Last updated: . This page is for general information and does not replace personal medical advice.