Pulmonary hypertension (PH) refers to increased blood pressure in the arteries that supply blood to the lungs (pulmonary arteries).
There are five types of pulmonary hypertension, which have been defined by the World Health Organization:
- Group 1 Pulmonary Arterial Hypertension (PAH) includes PAH with no known cause, when inherited, caused by toxins or drugs, caused by medical conditions such as connective tissue diseases, HIV, liver disease, congenital heart disease, and conditions that affect the veins and small blood vessels.
- Group 2 Pulmonary Hypertension includes PH that is associated with disorders affecting the left side of the heart, such as valvular heart disease, long-term high blood pressure, systolic dysfunction or diastolic dysfunction.
- Group 3 Pulmonary Hypertension includes PH associated with diseases of the lungs, such as chronic obstructive pulmonary disease (COPD), or interstitial lung diseases.
- Group 4 Pulmonary Hypertension includes PH caused by blood clots in the lungs.
- Group 5 Pulmonary Hypertension includes PH that is caused by other conditions such as blood disorders, sarcoidosis, metabolic disorders, or other disorders.