Venice classification of pulmonary hypertension(PH)
| 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 |
PAH: pulmonary arterial hypertension; COPD: chronic obstructive pulmonary disease.