A murmur is an unusual or extra sound of blood flowing. It may be from the blood passing through the abnormal heart valve or a condition that makes the heart beat fast, forcing it to handle more blood faster than usual. A heart has four chambers, separated by valves that regulate the level of blood that enters each chamber. A healthy valve prevents the blood from going in the wrong direction.

A healthy valve makes a lub-dub sound as it beats. But heart murmurs are the extra whooshing sound caused by turbulent blood passing through the heart valves. While some heart murmurs have no connection to any health condition, others may be a symptom of an overworked or damaged heart.

Symptoms
The harmless heart murmurs do not cause any symptoms. However, worrisome heart murmurs will show some of the following signs, which predominantly depend on the cause.

• Chest pain
• Gray or blue lips or fingernails
• Dizziness
• Swollen liver
• Fainting
• Persistent cough
• Swollen neck veins
• Shortness of breath
• Poor appetite with a lack of growth
• Heavy sweating with little to no activity
• Sudden swelling

Causes
Abnormal or turbulent blood flow across the heart valves causes heart murmurs. If the blood flows more rapidly than usual, it can cause a normal heart murmur called a physiologic or normal murmur. Such murmurs are common in the first few days after a child is born and during pregnancy, growth spurts, exercise, and childhood. These may come and go and get louder when a person’s heart beats faster. While they mostly go away within a short period, some may last a lifetime.

Normal heart murmurs do not indicate a problem with the heart; however, some heart murmurs are caused due to a heart problem or other conditions such as:

• Anemia
  Anemia affects blood viscosity and is one of the top causes of a heart murmur. It may lead to symptoms like fatigue and weakness.
• Congenital heart disease
  In some people, the heart has had a structural problem since birth. Some of the congenital heart defects include tetralogy of Fallot or septal defect.
• Carcinoid heart disease
  This is slow-growing cancer or tumor caused by extra hormones that affect one’s heart. A person with carcinoid syndrome may experience low blood pressure, diarrhea, and abdominal pain.
• Heart valve disease
  In this condition, one or more heart valves are not working well, preventing blood circulation. For instance, the valve may become stiff and not open or close the way or lead the blood in the wrong direction. Some other symptoms include swelling in the feet or ankles, pressure in the chest, shortness of breath, and heart palpitations.
• Overactive thyroid or hyperthyroidism
  When the thyroid gland makes too much thyroid hormone, it leads to hyperthyroidism. The condition may cause loss of appetite, anxiety, and rapid heartbeat.
• Endocarditis
  One of the primary causes of heart murmurs, endocarditis is a heart infection wherein germs like bacteria get into the bloodstream and attack the heart valves causing symptoms like sore throat, rash, chills, or fever.
• Hypertrophic cardiomyopathy
  It is a heart disease that makes the heart muscle larger, stiffer, and thicker than usual. It may be inherited or develop due to high blood pressure or aging. Other symptoms include heart palpitations, chest pain, fainting, shortness of breath, and fatigue.

Diagnosis
To begin with, doctors will use a stethoscope to hear one’s heartbeat and evaluate whether one has heart murmurs. If they think the condition is abnormal, they will recommend diagnostic tests like:

• Echocardiogram : A heart ultrasound to assess if there is a problem with the heart valves or structure.
• Chest X-ray : To understand if the heart muscles look bigger than typical.
• ECG : To examine the heart rate, rhythm, and electrical activity.

Treatment
Typically, heart murmurs may not need treatment. But abnormal murmurs are a sign of an underlying condition that demands medical attention. Doctors generally prescribe treatments to lower blood pressure, reduce damage to the valve, and improve blood flow across the valve. Moreover, some people with severe valve disease may need surgery to replace the defective valve. Further, if the heart valve problem hampers the blood flow through the heart significantly, it may increase pressure in the heart or other symptoms, and replacement or repair may be inevitable.