Pulmonary arterial hypertension (PAH) is a high blood pressure in the arteries that supply the lungs with blood. Patients with mild PAH, particularly young patients, may feel quite well and get breathless or tired only with vigorous exertion. Those with severe PAH may get breathless on minimal exertion and feel tired, exhausted and experience chest pain, forceful heart beats, dizzy turns, loss of appetite, and have swelling of the legs due to fluid...