Pulmonary hypertension (PH) is the broad, inclusive name for a group of several chronic diseases that affect the lungs and the heart. Some forms (or “subtypes”) of PH are rare as well as rapidly progressing, debilitating, and deadly. In pulmonary hypertension, the arteries that carry blood from the heart to the lungs narrow for reasons that are not yet entirely understood. The heart struggles to pump blood through the narrowed arteries, resulting in high blood pressure in the lungs and enlargement of the heart. Eventually, the overworked heart wears out, and heart failure and death can result.
There are five “classes” of PH:
Class 1: Pulmonary arterial hypertension (which includes idiopathic, heritable, drugs/toxins induced, associated with connective tissue disease, congenital heart disease, HIV, portal hypertension and others)
Class 2: Pulmonary hypertension due to left heart disease
Class 3: Pulmonary hypertension due to lung diseases and/or hypoxia
Class 4: Chronic thromboembolic pulmonary hypertension (CTEPH)
Class 5: PH with unclear and/or multifactorial mechanism
See the section on “classification” for further details.