A heart murmur is an extra or unusual "whooshing" or "swishing" sound heard during a heartbeat, caused by turbulent blood flow within or near the heart. While many are "innocent" (harmless) and common in children, others are "abnormal," resulting from structural heart defects, valve issues, or underlying conditions like anemia or fever.

Causes of Heart Murmurs:

Innocent (Benign): Common in children, teenagers, and during pregnancy due to high blood flow.

Abnormal: Caused by underlying structural problems, including:Valve Disease: Narrowing (stenosis) or leaking (regurgitation) of heart valves due to calcium deposits, infection (endocarditis), or rheumatic fever.Congenital Heart Defects: Structural issues present at birth.Conditions: Anemia, hyperthyroidism, or fever, which increase blood flow speed. 

Symptoms of an Abnormal Heart Murmur: Many murmurs cause no symptoms. If caused by an underlying condition, symptoms may include: Shortness of breath, chest pain, fainting or dizziness, blue skin around lips or fingertips, excessive sweat (especially with minimal exertion), swelling in legs, arms, or abdomen.