Classification	Targeted treatment available?
Group 1*: Pulmonary arterial hypertension	Yes
Including idiopathic, heritable, and HIV-associated; systemic sclerosis and other connective tissue disease; congenital heart disease; schistosomiasis; drug- and toxin-induced
Group 2: Pulmonary hypertension due to left heart disease	No
Including systolic and diastolic dysfunction and valvular heart disease
Group 3: Pulmonary hypertension due to lung diseases and/or hypoxia	No
Including chronic obstructive pulmonary disease, sleep-disordered breathing, and interstitial lung disease
Group 4: Chronic thromboembolic pulmonary hypertension	Yes
Group 5: Multifactorial pulmonary hypertension	No
Including metabolic, systemic, and hematologic disorders (sickle cell disease), and others