Updated clinical classification of pulmonary hypertension (from the fifth World Symposium on pulmonary hypertension, Nice, 2013)
| Disease | Classification |
| Pulmonary arterial hypertension (PAH) | 1 |
| Idiopathic PAH | 1.1 |
| Heritable | 1.2 |
| BMPR2 | 1.2.1 |
| ALK1, endoglin (with or without hereditary haemorrhagic telangiectasia), SMAD9, CAV1, KCNH3 | 1.2.2 |
| Unknown | 1.2.3 |
| Drug and toxin-induced | 1.3 |
| Associated with: | 1.4 |
| Connective tissue diseases | 1.4.1 |
| HIV infection | 1.4.2 |
| Portal hypertension | 1.4.3 |
| Congenital heart diseases | 1.4.4 |
| Schistosomiasis | 1.4.5 |
| Pulmonary veno-occlusive disease and/or pulmonary capillary haemangiomatosis | 1′ |
| Persistent pulmonary hypertension of the newborn | 1″ |
| Pulmonary hypertension owing to left heart disease | 2 |
| Left ventricular systolic dysfunction | 2.1 |
| Left ventricular diastolic dysfunction | 2.2 |
| Valvular disease | 2.3 |
| Congenital/acquired left heart inflow/outflow tract obstruction and congenital cardiomyopathies | 2.4 |
| Pulmonary hypertension owing to lung diseases and/or hypoxia | 3 |
| Chronic obstructive pulmonary disease | 3.1 |
| Interstitial lung disease | 3.2 |
| Other pulmonary diseases with mixed restrictive and obstructive pattern | 3.3 |
| Sleep disordered breathing | 3.4 |
| Alveolar hypoventilation disorders | 3.5 |
| Chronic exposure to high altitude | 3.6 |
| Developmental abnormalities | 3.7 |
| Chronic thromboembolic pulmonary hypertension | 4 |
| Pulmonary hypertension with unclear multifactorial mechanisms | 5 |
| Haematological disorders: chronic haemolytic anaemia, myeloproliferative disorders, splenectomy | 5.1 |
| Systemic disorders: sarcoidosis, pulmonary Langerhans cell histocytosis, lymphangioleiomyomatosis, neurofibromatosis, vasculitis | 5.2 |
| Metabolic disorders: glycogen storage disease, Gaucher disease, thyroid disorders | 5.3 |
| Others: tumoral obstruction, fibrosing mediastinitis, chronic renal failure, segmental PH | 5.4 |
BMPR2: bone morphogenetic protein receptor protein type 2; ALK1: activin receptor-like kinase type 1; CAV1: caveolin-1. Reproduced from [4] with permission from the publisher.