A doctor listening to a patient’s heart with a stethoscope

"I've been told I have a heart murmur." The phrase reaches my clinic at every age — the school medical, a pre-operative check, a routine health check — and it almost always arrives loaded with worry. Let me start with the most important point: a murmur is not a disease and not a diagnosis; it is simply a sound, and a great many are heard in perfectly healthy hearts. But precisely because the ear alone cannot always tell one from another, every new murmur deserves a proper work-up. Today I want to explain why — and why that work-up is far simpler than you might imagine.

An extra sound, not a disease

When I listen to a heart I hear its normal tones — that rhythmic "lub-dub" the valves make as they close. A murmur is an added sound, a kind of whooshing that appears when blood flows turbulently through the heart or the great vessels. Think of a river: while the channel is wide, the water runs silently; if it narrows, or the flow increases, you start to hear it.

Hold on to this: a murmur is a finding on examination, not a disease in itself. The stethoscope tells us that something is making a sound; working out what is making that sound is precisely what the work-up is for.

Innocent murmurs: when a healthy heart makes itself heard

Most murmurs are innocent, or functional: the sound of a completely normal heart. They are extremely common in childhood — a great many healthy children have a soft murmur picked up at some point as they grow; their chest wall is thin and their heart vigorous — and they also appear whenever the heart has to move more blood than usual:

Pregnancy: the volume of circulating blood increases and it is entirely normal for the heart to be "audible" for a few months.
Fever: the pulse speeds up temporarily and that increased flow can be heard.
Anaemia or an excess of thyroid hormone (hyperthyroidism): the heart compensates by moving more blood, faster.

There is no diseased heart here — just a healthy heart doing overtime, making a sound because it is working harder, not because anything is broken; indeed, the murmur usually disappears as the child grows, after the birth, or once the cause is put right.

Murmurs that do matter

Other murmurs, however, do reflect a structural problem that is worth diagnosing. The main ones are:

Valve disease (conditions affecting the heart's valves). The valves are the "doors" that keep blood flowing in one direction only. They can narrow (stenosis), forcing the heart to push against a half-closed door, or fail to shut properly and let some of the blood leak backwards (regurgitation). Both create turbulence... and murmurs.
Age-related valve degeneration: over the years some valves — above all the aortic valve — stiffen and calcify. It is the most frequent cause of a new murmur from the age of 65-70 onwards, which is why at those ages I never assume a murmur "must have always been there".
Hypertrophic cardiomyopathy: an abnormal thickening of the heart muscle, often inherited, which can obstruct the outflow of blood and is also worth identifying because of what it may mean for the rest of the family.
Congenital heart conditions: defects present from birth, such as small holes between the chambers of the heart, which sometimes do not show themselves until adult life.

Why every new murmur should be investigated, even if you feel well

"If I feel fine, do I really need this?" patients often ask me. Yes — for three reasons.

The first is a matter of honesty: listening with a stethoscope tells us a great deal, but it cannot always tell us for certain whether a murmur is innocent or not. There are significant valve problems that make very little noise, and striking murmurs with absolutely nothing behind them.

The second: valve disease tends to stay silent for years, because the heart is a remarkably long-suffering organ that adapts to the extra workload without causing symptoms until a late stage. Catching it early changes everything: it allows straightforward follow-up and lets us choose the best moment to act, rather than discovering it late, once the heart has already paid the price.

And the third: because investigating it is simple, quick and painless; rarely in medicine do we get so much information for so little effort.

That said, although an isolated murmur is almost never urgent, certain accompanying symptoms change the picture entirely: tiredness out of proportion to what you are doing, breathlessness, chest pain or tightness, dizziness or blackouts, swollen legs, or a persistent fever without a clear cause... With any of these, my advice is not to delay the assessment. It does not mean something serious is going on — those symptoms often have another explanation — but that combination goes to the front of the queue.

Investigating a murmur is not about hunting for a disease: it is about putting a name to a sound. And most of the time, that name is "nothing".

How we investigate it: an answer in a single visit

The work-up of a murmur is one of the most rewarding parts of my specialty: it almost always gives a clear, quick answer. It begins with listening to you and examining you — your story, your family history, when the murmur was first detected. Then an electrocardiogram, the heart's electrical "snapshot", which offers clues about its rhythm and size.

And the key test is the colour Doppler echocardiogram (an ultrasound scan of the heart), painless and radiation-free, which I perform in the same consultation. With it I watch the valves opening and closing in real time, I measure the chambers and the strength of the heart muscle, and the colour Doppler "paints" the blood flow on the screen: a leak or a narrowing can not only be seen — it can be measured. In a single visit we confirm or rule out the cause of the murmur. Only in specific cases do we add a Holter monitor (a continuous recording of your heart rhythm over 24-48 hours) or an exercise stress test, according to clinical judgement.

And after the work-up, what then?

If the murmur is innocent — the most frequent outcome, especially in children and young people — the consultation ends with the best possible news: a healthy heart and a normal life, sport included, with no medication and no follow-up needed on this account. That report is worth its weight in gold, above all when the scare was a big one.

If we do find valve disease, that does not mean an operation or immediate treatment either: the great majority need nothing more than periodic follow-up with an echocardiogram, with check-ups ranging from every six months for the most advanced lesions to every few years for mild ones, and habits that look after the heart. Treatment, when it does eventually become necessary, is planned at the right moment: keep a close watch so we can act in good time — that is the strategy.

So if you, or someone in your family, have been told there is a murmur, take a breath: the most likely answer is that it is nothing. But do not leave it hanging; putting a name to it takes a single consultation. I investigate murmurs by appointment at my clinics in Valencia and Dénia, in English as well as Spanish, and few things sum up better how I understand this profession: looking in good time, calmly and with real data, because the best medicine will always be good prevention.

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This article is for information only and does not replace individual assessment or advice from a healthcare professional. For acute symptoms such as severe chest pain, call 112.

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