Heart Murmur in adults and children: Causes, symptoms & when it's serious
I've Been Told I Have a Heart Murmur! Should I Be Worried?
Being told you have a heart murmur often raises more questions than answers. Is it serious? Does it mean your heart is damaged? Should you change how you live?
The honest answer is: it depends, and that's exactly why it needs to be evaluated properly.
Some murmurs are completely innocent(normal) and need no treatment whatsoever. Others are early signs of a valve problem or a structural defect that, if left unmonitored, can become serious over time. The murmur itself is not a diagnosis; it is a signal that points toward one of two very different realities, and only the right tests can tell you which one applies to you.
This article walks you through what a murmur actually is, what symptoms matter, when to act fast, and how doctors figure out what's behind it.
What exactly is a Heart Murmur?
A heart murmur is an extra sound a doctor picks up through a stethoscope while listening to your heartbeat. It is an additional noise between the normal lub-dub of the heart valves closing.
It is not a diagnosis or a disease; it is a physical exam finding that instigates the doctor to treat further
It indicates that blood moving through the heart or across a valve is producing an audible sound
It can be present from birth or develop later in life
Many people have had one for years or their entire lives without ever knowing
Key point: A murmur is what the doctor hears. The cause behind it is what actually determines whether it matters.
Does a Heart Murmur always mean something is wrong?
Not necessarily, but it always deserves a proper answer.
Heart murmurs are actually the single most common reason children are referred to a paediatric cardiologist. Research estimates that as many as 72% of children will have a murmur at some point during childhood or adolescence, with some resolving on their own and others persisting into adulthood.
Importantly, of all new murmurs referred to a paediatric cardiologist, fewer than 1% turn out to be caused by congenital heart disease. Much of the concern among doctors comes from not wanting to miss a serious diagnosis while the child appears otherwise healthy, which is why referral and evaluation are standard practice even when a murmur seems harmless.
Heart murmurs fall into two distinct categories:
Innocent (Functional) Murmurs
No underlying structural problem in the heart
Extremely common in children; many resolve without any intervention as the child grows
Can occur in healthy adults too, during pregnancy, fever, anaemia, or physical exertion
Carry no health risk and need no treatment
Abnormal (Pathological) Murmurs
Reflect an actual problem, a valve defect, a hole in the heart, or another structural issue
Require investigation to determine the severity and the right course of action
More prevalent in adults over 65 due to natural valve stiffening and calcification with age
What causes a Heart Murmur?
Innocent murmurs can be triggered by:
Periods of rapid growth in children
Pregnancy (due to increased blood volume and flow)
Fever or acute infection
Anaemia (low red blood cell count reduces blood thickness, increasing flow speed)
Vigorous physical activity
An overactive thyroid (hyperthyroidism)
Abnormal murmurs may result from:
Valve narrowing (stenosis): the valve opening is too tight, restricting blood flow
Valve leaking (regurgitation): the valve does not close fully, allowing blood to flow backward
Congenital heart defects: structural issues present from birth, such as holes between heart chambers (ventricular or atrial septal defects)
Infective endocarditis: bacterial infection of the heart's inner lining, often affecting valves
Rheumatic fever: a complication of untreated strep throat that can scar heart valves over time
Calcification: hardening and thickening of valves with age, particularly common after 65
According to the CDC, congenital heart defects affect nearly 1% of all births in the United States, which approximately 40,000 babies each year, making them the most common type of birth defect, and many are first detected as a murmur.
Can a Heart Murmur go away on its own?
It depends entirely on the type and cause-
Type | Does It Resolve? |
Innocent murmur in a child | Often, yes, many disappear before adulthood |
Murmur from a temporary cause (fever, anaemia) | Yes, once the underlying cause is treated |
Murmur from valve disease | No, requires monitoring or intervention |
Murmur from a congenital defect | Usually not without a procedure or surgery |
Innocent murmurs in children frequently go away on their own as the heart grows
If your murmur was triggered by something correctable like iron-deficiency anaemia, then resolving that condition often eliminates the murmur.
Murmurs rooted in structural problems do not resolve on their own and tend to worsen if left untreated.
What symptoms should I watch for?
An innocent murmur produces no symptoms whatsoever. But if you are experiencing symptoms alongside a murmur, that is a red flag that warrants prompt medical attention.
Symptoms that may indicate an abnormal murmur:
Chest pain or pressure, especially during activity
Shortness of breath at rest, lying flat, or with minimal exertion
Dizziness or lightheadedness
Fainting or near-fainting (syncope)
Rapid or irregular heartbeat (palpitations)
Unexplained persistent fatigue
Swelling in the legs, ankles, or abdomen is a possible sign of reduced cardiac output
A bluish tinge to the lips or fingertips more common in congenital defects
When is a Heart Murmur considered serious?
Not every murmur needs treatment but some do point to a real problem that can quietly worsen if ignored.
A murmur is worth taking seriously when it is connected to one of the following:
A narrowed aortic valve (aortic stenosis): The valve opening becomes too tight, making the heart work harder to push blood through. It is the most common serious valve condition in older adults, affecting close to 10% of people over 80.
A leaking mitral valve (mitral regurgitation): Instead of closing fully, the valve lets blood slip back the wrong way. Over the years, this puts a strain on the heart and can cause it to gradually enlarge.
A hole in the heart or an unclosed vessel: Conditions like VSD (a gap between the heart's two lower chambers) or PDA (a blood vessel that should close after birth but doesn't) are the most common structural defects found in children with abnormal murmurs.
A heart valve infection (endocarditis): Bacteria settle on the valve and cause damage quickly. This needs urgent treatment.
A murmur in a newborn: Murmurs in newborns are taken more seriously than in older children because the risk of an underlying defect is higher. Doctors generally recommend a specialist review within the first week of life if the murmur doesn't settle before the baby goes home.
Valve-related heart disease affects an estimated 2.5% of adults overall — but that figure jumps to over 13.2% in people aged 75 and above. Many of these cases are picked up first through a murmur.
How do doctors grade murmur intensity? Levine Scale (I to VI):
Grade | What it means in simple terms |
I | Very soft and difficult to hear unless the doctor listens carefully |
II | Soft, but easily heard with a stethoscope |
III | Noticeably audible, without any vibration felt on the chest |
IV | Loud enough that a vibration can be felt when touching the chest |
V | Very loud and can be heard even when the stethoscope is only lightly placed on the chest |
VI | Extremely loud and can be heard even when the stethoscope is slightly away from the skin |
Grade I–II murmurs are far more likely to be innocent. Grade III and above are more commonly linked to an underlying heart condition, though only an echocardiogram can confirm this.
Should i see a doctor if i have a Heart Murmur?
Yes, at least once, for a proper evaluation.
Even a murmur that turns out to be innocent deserves a confirmed diagnosis. Living with uncertainty is not necessary when a simple echo can resolve it.
See a doctor promptly if:
You have just been told you have a murmur and it has never been formally assessed
You develop any of the symptoms listed above even mild ones
Your child has a murmur that has not been reviewed by a paediatrician or paediatric cardiologist
Go to the emergency room immediately if you experience:
Sudden chest pain or tightness
Fainting or loss of consciousness
Difficulty breathing at rest
Bluish lips or fingertips
What to tell your doctor:
When you first learned about the murmur
Any symptoms you have noticed, even vague ones
Family history of heart disease or unexplained sudden cardiac death
Any recent infections, particularly strep throat
Bottom Line
Most heart murmurs are innocent and require nothing beyond a one-time confirmation. But the only way to know for certain is to have it properly evaluated.
If you've been told you have one:
Do not panic as the majority are benign
Do get an echocardiogram to confirm the type
If you notice symptoms, you can use symptom-assessment tool like Clyvera to help determine whether they may require prompt medical attention. However, it should not replace a doctor's evaluation.
Keep follow-up appointments if your doctor recommends ongoing monitoring
A heart murmur is a sound. Whether it is significant depends entirely on what is making it.
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