Pulmonary hypertension is a condition in which there is an elevation of the pulmonary artery pressure. The condition can occur as a result of chronic lung disease, increased pulmonary blood flow due to atrial septal defect, ventricular septal defect or patent ductus arteriosus, left ventricular failure, mitral stenosis, recurrent pulmonary emboli or it can be idiopathic (no known aetiology). Idiopathic pulmonary hypertension is rare and primarilly affects young women.