Table 2. Pulmonary hypertension classification.

Group 1: pulmonary arterial hypertension

Idiopathic (IPAH)

Heritable (HPAH)

Drug and toxin induce PAH

Associated with (APAH)

Connective tissue disorder

HIV infection

Portal hypertension

Congenital heart disease

Schistosomiasis

PAH long-term responders to CCB

PAH with venous/capillary involvement (PVOD/PCH)

Persistent pulmonary hypertension of the newborn syndrome

Group 2: left heart disease

PH due to HFPEF

PH with HFREF

Valvular heart disease

CV (acquired or congenital) leading to post-capillary PH

Group 3: hypoxia or lung disease

Obstructive lung disease

Restrictive lung disease

Other lung disease with mixed restrictive/obstructive pattern

Hypoxia without lung disease

Developmental lung disorders

Group 4: PH due to pulmonary artery obstruction

Chronic thromboembolic PH (CTEPH)

Other pulmonary artery obstructions

Group 5: miscellaneous

Hematological disorders

Systemic and metabolic disorders

Others

Complex congenital heart disease

CCB, calcium-channel blocker; PH, pulmonary arterial hypertension; PAH, pulmonary arterial hypertension.