TABLE 1

Updated World Health Organization classification of pulmonary hypertension

Group 1:
Pulmonary arterial hypertension
Idiopathic
Heritable
BMPR2 mutation
 Other mutations
Drug- and toxin-induced
Associated with:
 Connective tissue disease
 Human immunodeficiency virus (HIV) infection
 Portal hypertension
 Congenital heart disease
 Schistosomiasis
Pulmonary veno-occlusive disease or pulmonary capillary hemangiomatosis
 Idiopathic
 Heritable
  EIF2AK4 mutation
  Other mutations
 Drug-, toxin-, and radiation-induced
 Associated with:
  Connective tissue disease
  HIV infection
Persistent pulmonary hypertension of the newborn
Group 2:
Pulmonary hypertension due to left heart disease
Left ventricular systolic dysfunction
Left ventricular diastolic dysfunction
Valvular disease
Congenital or acquired left heart inflow or outflow tract obstruction and congenital cardiomyopathies
Congenital or acquired pulmonary vein stenosis
Group 3:
Pulmonary hypertension due to lung diseases, hypoxia, or both
Chronic obstructive pulmonary disease
Interstitial lung disease
Other pulmonary diseases with mixed restrictive and obstructive pattern
Sleep-disordered breathing
Alveolar hypoventilation disorders
Chronic exposure to high altitude
Developmental lung diseases
Group 4:
Chronic thromboembolic pulmonary hypertension and other pulmonary artery obstructions
Chronic thromboembolic pulmonary hypertension
Other pulmonary artery obstructions
 Angiosarcoma
 Other intravascular tumors
 Arteritis
 Congenital pulmonary artery stenosis
 Parasites (hydatidosis)
Group 5:
Pulmonary hypertension with unclear or multifactorial mechanisms
Hematologic disorders: chronic hemolytic anemia, myeloproliferative disorders, splenectomy
Systemic disorders, sarcoidosis, pulmonary histiocytosis, lymphangioleiomyomatosis
Metabolic disorders: glycogen storage disease,
Gaucher disease, thyroid disorders
Others: pulmonary tumoral thrombotic microangiopathy, fibrosing mediastinitis, chronic renal failure (with or without dialysis), segmental pulmonary hypertension
  • Reproduced with permission of the European Society of Cardiology and the European Respiratory Society. European Respiratory Journal Oct J 2015; 46(4):903–975. doi:10.1183/13993003.01032-2015