Pulmonary Arterial Hypertension (PAH) is continuous high blood pressure in the pulmonary artery. PAH is a serious condition for which there are treatments but no cure. Treatment benefits many patients. Clinical research involves investigations into the molecular, genetic and environmental causes of pulmonary hypertension. Research also includes: primary pulmonary hypertension, pulmonary hypertension secondary to heart disease and new therapies to treat patients diagnosed with hypertension.