Pulmonary hypertension (PH) is a haemodynamic state where the mean pulmonary artery pressure measured at cardiac catheterisation is 25 mmHg or more. Precapillary PH arises from increased resistance to blood flow in the pulmonary arterioles and postcapillary PH from elevated left atrial pressure. In postcapillary PH the cause is left heart disease whereas precapillary PH may be caused by any other form of PH. Patients develop symptoms only when the disease is advanced. Symptoms at presentation are non specific. Adults almost always present with breathlessness and may also complain of exercise-induced dizziness or syncope and angina. An echocardiogram is the best investigation to ascertain the probability of PH.