1. PAH |
1.1. Idiopathic PAH |
1.2.Heritable |
1.2.1 BMPR2 gene mutation |
1.2.2 ALK1, endoglin (with or without hereditary haemorrhagic telangiectasia) gene mutation |
1.2.3 Unknown |
1.3. Drug- and toxin-induced |
1.4. APAH |
1.4.1. Connective tissue diseases |
1.4.2. HIV infection |
1.4.3. Portal hypertension |
1.4.4. Congenital heart disease |
1.4.5. Schistosomiasis |
1.4.6. Chronic haemolytic anaemia |
1.5. Persistent PH of the newborn |
1′. Pulmonary veno-occlusive disease and/or pulmonary capillary haemangiomatosis |
2. PH due to left heart disease |
2.1. Systolic dysfunction |
2.2. Diastolic dysfunction |
2.3. Valvular disease |
3. PH due to lung diseases and/or hypoxia |
3.1. Chronic obstructive pulmonary disease |
3.2. Interstitial lung disease |
3.3. Other pulmonary diseases with mixed restrictive and obstructive pattern |
3.4. Sleep-disordered breathing |
3.5. Alveolar hypoventilation disorders |
3.6. Chronic exposure to high altitude |
3.7. Developmental abnormalities |
4. CTEPH |
5. PH with unclear and/or multifactorial mechanisms |
5.1. Haematological disorders: myeloproliferative disorders and splenectomy |
5.2. Systemic disorders, sarcoidosis, pulmonary Langerhans cell histiocytosis, lymphangioleiomyomatosis, neurofibromatosis and vasculitis |
5.3. Metabolic disorders: glycogen storage disease, Gaucher disease and thyroid disorders |
5.4. Others: tumoural obstruction, fibrosing mediastinitis and chronic renal failure on dialysis |
PAH: pulmonary arterial hypertension; BMPR2: bone morphogenetic protein receptor, type 2; ALK1: activin receptor-like kinase 1; APAH: associated PAH; CTEPH: chronic thromboembolic PH.