Mean PA pressure >25 mmHg as assessed by right heart catheterization
Since right ventricle is dependent on preload, RV contractility and afterload, severe<unk>  arterial<unk>  causes pathological changes to right ventricle
Since right ventricle is dependent on preload, RV contractility and afterload, severe<unk>  arterial<unk>  causes pathological changes to right ventricle
Group 1:<unk>  arterial<unk> 
Idiopathic
Associated with:
Drugs or toxins
Connective tissue disorders
HIV
Portal<unk> 
Congenital heart disease
Group 2:<unk>  due to left heart disease
Associated with:
Coronary artery disease<unk> 
Valvular disease
Advanced age
Group 3:<unk>  due to lung diseases
Associated with:
COPD
Interstitial lung disease
Any other lung disease causing hypoxemia
Group 4:<unk>  due to chronic thromboembolic disease
Group 5:<unk>  of unclear multifactorial mechanisms
Associated with:
Sarcoidosis
Sickle cell anemia
Chronic hemolytic anemia
Splenectomy
Metabolic disease
Idiopathic
Associated with:
Drugs or toxins
Connective tissue disorders
HIV
Portal<unk> 
Congenital heart disease
Drugs or toxins
Connective tissue disorders
HIV
Portal<unk> 
Congenital heart disease
Associated with:
Coronary artery disease<unk> 
Valvular disease
Advanced age
Coronary artery disease<unk> 
Valvular disease
Advanced age
Associated with:
COPD
Interstitial lung disease
Any other lung disease causing hypoxemia
COPD
Interstitial lung disease
Any other lung disease causing hypoxemia
Associated with:
Sarcoidosis
Sickle cell anemia
Chronic hemolytic anemia
Splenectomy
Metabolic disease
Sarcoidosis
Sickle cell anemia
Chronic hemolytic anemia
Splenectomy
Metabolic disease
Heritable
Idiopathic
Chronic hypoxia
Chronic thromboembolic disease
Vasculitis
Autoimmune disease
Toxic exposures
Chronic renal failure on dialysis
Myeloproliferative disorders
Pulmonary hypertension
Pulmonary
Bronchopulmonary dysplasia
Airway obstruction
Empyema
Anaphylaxis
Pneumoconiosis
Angioedema