Group 1: Pulmonary Arterial Hypertension (PAH)
Although PAH is what most people think of when they hear about PH, it only represents ~3% of all types of PH. In PAH, the primary problem is narrowed and stiff arteries in the lungs, which increases the blood pressure and stresses the right side of the heart. PAH can occur without a clear cause (idiopathic), be inherited, or be related to other conditions or diseases. There are several drugs that can cause PAH in adults, the most notorious being methamphetamines and diet/weight-loss pills (e.g.
Fen-Phen). PAH can also develop in association with HIV, connective tissue disease (especially scleroderma), liver disease, congenital (at birth) heart disease, and schistosomiasis (a parasitic infection occurring in tropical areas). PAH can be treated with pulmonary vasodilators to relax and open the arteries in the lungs and other therapies
. Treating any associated disease and stopping any potentially harmful drugs is essential.