Haemolytic anemia is a form of anemia due to haemolysis, the abnormal breakdown of red blood cells (RBCs), either in the blood vessels (intravascular haemolysis) or elsewhere in the human body (extravascular). This most commonly occurs within the spleen, but also can occur in the reticuloendothelial system or mechanically (prosthetic valve damage). Haemolytic anemia accounts for 5% of all existing anemias. It have numerous possible consequences, ranging from general symptoms to life-threatening systemic effects. The general classification of haemolytic anemia is either intrinsic or extrinsic. Treatment depends on the type and cause of the haemolytic anemia. Symptoms of haemolytic anemia are similar to other forms of anaemia (fatigue and shortness of breath), but in addition, the breakdown of red cells leads to jaundice and increases the risk of particular long-term complications, such as gallstones and pulmonary hypertension. Chronic haemolysis  leads to an increased excretion of bilirubin into the biliary tract, which in turn may lead to gallstones. The continuous release of free haemoglobin has been linked with the development of pulmonary hypertension (increased pressure over the pulmonary artery); this, in turn, leads to episodes of syncope (fainting), chest pain, and progressive breathlessness. Pulmonary hypertension eventually causes right ventricular heart failure, the symptoms of which are peripheral edema.