Group I: PAH |
Idiopathic PAH |
Familial PAH |
PAH associated with: |
Connective tissue disease |
Congenital systemic-to-pulmonary shunts |
Portal hypertension |
HIV infection |
Drugs and toxins |
Other (e.g. thyroid disorders, glycogen storage disease, Gaucher's disease, hereditary haemorrhagic telangiectasia, haemoglobinopathies, myeloproliferative disorders, splenectomy) |
PAH associated with significant venous or capillary involvement: |
Pulmonary veno-occlusive disease |
Pulmonary capillary haemangiomatosis |
Persistent PH of the newborn |
Group II: PH associated with left heart diseases |
Group III: PH associated with respiratory diseases and/or hypoxaemia (including COPD) |
Group IV: PH due to chronic thrombotic and/or embolic disease |
Group V: Miscellaneous group |
e.g. sarcoidosis, histiocytosis X and lymphangiomatosis |