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What Causes Heart Murmurs?

Nat Robinson
Nat Robinson

Heart murmurs are abnormal heart sounds. Generally, the heart makes a lub-dupp like sound when beating. When a person has a heart murmur, his heartbeat may make a swishing sound. This difference is usually detected when a doctor listens to the person's heart with a stethoscope. A heart murmur may be congenital or present at birth or develop later in a person's life.

In many cases, heart murmurs are harmless. Many people with a heart murmur have a perfectly normal heart. These individuals are said to have an innocent heart murmur. Usually when heart disease or some other type of cardiovascular irregularity causes the murmur, the condition is known as an abnormal murmur. Typically, different types of murmurs have different causes.

Heart murmurs can be detected through use of a stethoscope.
Heart murmurs can be detected through use of a stethoscope.

There are cases in which innocent heart murmurs have no definite cause. Sometimes, they are caused by different health problems. Anemia, hyperthyroidism and fevers can cause this type of murmur. Strenuous physical exercise and a recent surgery on the heart can be other innocent causes. Often, pregnancy can cause an innocent heart murmur as well.

Heart valve problems frequently cause abnormal heart murmurs. The problem may be a leaking in a heart valve. This is known as regurgitation. Another problem could be aortic valve stenosis. With stenosis of this nature, there is a narrowing of the valve. Either of these types of valve problems can disrupt the proper blood flow in the valve and cause a murmur.

An overactive thyroid may cause heart murmurs.
An overactive thyroid may cause heart murmurs.

Abnormal heart murmurs may also be caused by endocarditis. This is an infection of the heart's valves and inner lining. The infection causes significant inflammation in these areas. In most cases, germs and bacteria cause endocarditis. Although anyone can get this infection, it generally affects individuals with existing heart problems.

Sometimes, holes in the heart can cause a murmur. This abnormality is classified as an abnormal heart murmur cause. Heart murmurs from this cause can be minor or very serious. The seriousness of this type of murmur can depend on many factors. Generally, the location and size of the hole can influence the seriousness of the condition.

Holes in the heart may cause a heart murmur.
Holes in the heart may cause a heart murmur.

Rheumatic fever can cause heart murmurs as well. This is a type of inflammatory disease, which is usually caused by streptococcus bacteria. Strep throat is also caused by this bacteria. Rheumatic fever can be very dangerous. It can damage the heart and in particular the valves. The damage can be permanent and a murmur can result from the damage.

An individual with an innocent heart murmur may not need any special treatment. If a general physician discovers a heart murmur that she believes is serious, the patient may be referred to a cardiologist. A cardiologist may order tests such as a chest X-ray, an electrocardiogram (EKG) and a computerized tomography (CT) scan. The doctor will order these tests to find the cause of the heart murmur, so that she can begin the proper treatment. Although, in many cases, abnormal heart murmurs will not require any particular treatment either.

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    • Heart murmurs can be detected through use of a stethoscope.
      By: leelaryonkul
      Heart murmurs can be detected through use of a stethoscope.
    • An overactive thyroid may cause heart murmurs.
      By: brankatekic
      An overactive thyroid may cause heart murmurs.
    • Holes in the heart may cause a heart murmur.
      By: drubig-photo
      Holes in the heart may cause a heart murmur.
    • Individuals who experience a heart murmur may be referred to a cardiologist.
      By: Robert Kneschke
      Individuals who experience a heart murmur may be referred to a cardiologist.
    • Some heart murmurs are harmless, while others can indicate cardiovascular problems.
      By: pirotehnik
      Some heart murmurs are harmless, while others can indicate cardiovascular problems.
    • Fever and anemia may result in "innocent" heart murmurs that pose little danger.
      By: Ocskay Bence
      Fever and anemia may result in "innocent" heart murmurs that pose little danger.
    • Some people experience heart murmur as a result of heart valve disease.
      By: p6m5
      Some people experience heart murmur as a result of heart valve disease.