Table 1 Clinical classification of pulmonary hypertension (Simonneau et al. 2013)

1. Pulmonary arterial hypertension

 1.1 Idiopathic

 1.2 Heritable

 1.2.1 BMPR2 mutation

 1.2.2 Other mutations

 1.3 Drugs and toxins induced

 1.4 Associated with:

 1.4.1 Connective tissue disease

 1.4.3 Portal hypertension

 1.4.4 Congenital heart disease

 1.4.5 Schistosomiasis

 1′. Pulmonary veno-occlusive disease and/or pulmonary capillary haemangiomatosis

 1′.1 Idiopathic

 1′.2 Heritable

 1′.2.1 EIF2AK4 mutation

 1′.2.2 Other mutations

 1′.3 Drugs, toxins and radiation induced

 1′.4 Associated with:

 1′.4.1 Connective tissue disease

 1′.4.2 HIV infection

 1″. Persistent pulmonary hypertension of the newborn

2. Pulmonary hypertension due to left heart disease

 2.1 Left ventricular systolic dysfunction

 2.2 Left ventricular diastolic dysfunction

 2.3 Valvular disease obstruction and congenital cardiomyopathies

 2.5 Congenital /acquired pulmonary veins stenosis

3. Pulmonary hypertension 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 lung diseases (Web Table III)

4. Chronic thromboembolic pulmonary hypertension and other pulmonary artery obstructions

 4.1 Chronic thromboembolic pulmonary hypertension

 4.2 Other pulmonary artery obstructions

 4.2.1 Angiosarcoma

 4.2.2 Other intravascular tumors

 4.2.3 Arteritis

 4.2.4 Congenital pulmonary arteries stenoses

 4.2.5 Parasites (hydatidosis)

5. Pulmonary hypertension with unclear and/or multifactorial mechanisms

 5.1 Haematological disorders: chronic haemolytic anaemia, myeloproliferative disorders, splenectomy

 5.2 Systemic disorders: sarcoidosis, pulmonary histiocytosis, lymphangioleiomyomatosis, neurofibromatosis

 5.3 Metabolic disorders: glycogen storage disease, Gaucher disease, thyroid disorders

 5.4 Others: pulmonary tumoral thrombothic microangiopathy, osing mediastinitis, chronic renal failure (with/without dialysis), segmental pulmonary hypertension