Table 1 Clinical classification of pulmonary hypertension

1

Pulmonary arterial hypertension

1.1

Idiopathic pulmonary arterial hypertension

1.2

Heritable

1.2.1

Bone morphogenetic protein receptor 2

1.2.2

Activin receptor-like kinase type 1, endoglin

1.2.3

Unknown

1.3

Drug- and toxin-induced

1.4

Associated with

1.4.1

Connective tissue diseases

1.4.2

Human immunodeficiency virus (HIV) infection

1.4.3

Portal hypertension

1.4.4

Congenital heart diseases

1.4.5

Schistosomiasis

1.4.6

Chronic hemolytic anemia

1.5

Persistent pulmonary hypertension of the newborn

1’

Pulmonary veno-occlusive disease and/or pulmonary capillary hemangiomatosis

2

Pulmonary hypertension owing to left heart disease

3

Pulmonary hypertension owing to lung diseases and/or hypoxia

4

Chronic thromboembolic pulmonary hypertension

5

Pulmonary hypertension with unclear multifactorial mechanisms