Different Types of PH

Healthcare providers use the blanket term “pulmonary hypertension” to describe five types of the disease, each of which has its own cause and name.

 PAH happens when the arteries to the lungs become damaged without a clear reason. For example, these tiny conduits for blood may become narrower. The narrowing restricts blood flow and elevates blood pressure inside the lungs. This narrowing also taxes the heart, which must use more force to push blood through the arteries.

The right side of the heart must pump harder to overcome this higher pressure and push blood to the lungs. The added effort causes the heart to enlarge over time. The right side of the heart also stiffens, further reducing its pumping capacity. Eventually, the right side of the heart becomes so weak it can no longer adequately circulate blood—a condition called right-sided heart failure.

This type of PH has five types of causes. It can be idiopathic in nature, meaning the cause is unknown. PAH also can be genetically inherited, running in families. The use of drugs or illegal substances also may give rise to PAH. Problems with the heart at birth, known as congenital heart disease, can lead to PAH, and so can other conditions, including connective tissue disorders like lupus, scleroderma, and HIV.

Group 2 PH stems from left-sided heart valve disease, which includes mitral valve or aortic valve disease. Mitral valve disease involves complications with the valve that separates the heart’s left chambers: the left atrium and left ventricle. Aortic valve disease involves problems with the valve situated between the heart’s lower-left chamber (the left ventricle) and the aorta (a major artery).

This PH classification stems from issues with the lungs, including sleep apnea, pulmonary fibrosis (the accumulation of scar tissue between air sacs in the lungs), and chronic obstructive pulmonary disease (COPD)

Blood clots in the lungs, known as pulmonary emboli, and other clotting disorders can lead to this PH classification.

Group 5 of PH stems from a mix of other diseases and conditions. For example, blood disorders such as polycythemia vera (a type of blood cancer in which the body makes excess red blood cells) and essential thrombocythemia (a blood disorder involving excess production of platelets) can cause Group 5 PH. So can inflammatory disorders such as sarcoidosis, a disease in which pockets of inflammation arise in the body. Metabolic disorders, such as glycogen storage disease, a condition in which the body lacks an enzyme to properly store or use glycogen, can lead to Group 5 PH, and so can kidney disease, with some tumors causing clots or physical compression of the pulmonary artery from nearby tissues.