Table 1: Classification of pulmonary hypertension (Dana-point [7]).

(1) Pulmonary artery hypertension
  (1.1) Idiopathic (IPAH)
  (1.2) Hereditary (HPAH)—BMPR2, ALK-1, endoglin
  (1.3) Drug and toxin induced
  (1.4) Associated pulmonary artery hypertension (APAH)
    (1.4.1) Connective tissue disorders
    (1.4.2) HIV infection
    (1.4.3) Portal hypertension
    (1.4.4) Congenital heart diseases
    (1.4.5) Schistosomiasis
    (1.4.6) Chronic hemolytic anemia
    (1.4.7) Persistent newborn pulmonary hypertension
  (1.5) Pulmonary veno-occlusive disease and/or pulmonary capillary hemangiomatosis (PCH)
(2) Pulmonary hypertension caused by left-heart disease
  (2.1) Systolic dysfunction
  (2.2) Diastolic dysfunction
  (2.3) Valve disease
(3) Pulmonary hypertension secondary to pulmonary diseases and/or hypoxemia
  (3.1) Chronic obstructive pulmonary disease
  (3.2) Interstitial pulmonary disease
  (3.3) Other pulmonary diseases with mixed restrictive and obstructive patterns
  (3.4) Sleep-disordered breathing
  (3.5) Alveolar hypoventilation disorders
  (3.6) Chronic high-altitude exposure
  (3.7) Developmental abnormalities
(4) Chronic thromboembolic pulmonary hypertension (CTEPH)
(5) Pulmonary hypertension with unclear or multifactorial mechanisms
  (5.1) Hematological disorders: myeloproliferative and splenectomy
  (5.2) Systemic disorders: sarcoidosis, pulmonary Langerhans cell histiocytosis, lymphangioleiomyomatosis, neurofibromatosis, and vasculitis
  (5.3) Metabolic disorders: glycogen storage disease, Gaucher's disease, and thyroid disorders
  (5.4) Others: tumoral obstruction, fibrous mediastinitis, and chronic renal failure with dialysis