Heart murmurs are generated by turbulent flow of blood and a murmur to be heard as turbulent flow must require pressure difference of at least 30 mm of Hg between the chambers and the pressure dominant chamber will out flow the blood to non dominant chamber in diseased condition which leads to Left-to-right shunt or Right-to-left shunt based on the pressure dominance. Turbulence may occur inside or outside the heart; if it occurs outside the heart then the turbulence is called Bruit. Murmurs may be physiological (benign) or pathological (abnormal). Abnormal murmurs can be causes by stenosis restricting the opening of a heart valve, resulting in turbulence as blood flows through it. Abnormal murmurs may also occur with valvular insufficiency (regurgitation), which allows backflow of blood when the incompetent valve closes with only partial effectiveness. Different murmurs are audible in different parts of the cardiac cycle, depending on the cause of the murmur.