NPPB and idiopathic pulmonary arterial hypertension: Currently, IPAH is diagnosed by a careful history and physical examination, chest radiography, electrocardiogram, echocardiography (ECHO), right heart catheterization (RHC), arterial blood gas and serum N-terminal pro-B-type natriuretic peptide or B-type natriuretic peptide (NT-proBNP or BNP) testing, as well as ventilation–perfusion (V/Q) scanning, chest computed tomography and pulmonary function testing to rule out other diseases1,2.