Idiopathic Pulmonary Arterial Hypertension (IPAH) is a progressive disease of the pulmonary vasculature without any known underlying risk factors. For the diagnosis Pulmonary Artery Hypertension (PAH). the mean Pulmonary Artery Pressure (mPAP) should be persistently more than 20 mmHg at rest. Early diagnosis. https://www.socialstudiesscholar.com/