Learn About Pulmonary Arterial Hypertension

Pulmonary arterial hypertension (PAH) is a specific type of pulmonary hypertension that is caused when the tiny arteries in your lung become thickened and narrowed. This narrowing blocks the blood flow through the lungs which raises the blood pressure in the lungs. This causes your heart to have to work harder and over time the heart loses ability to effectively pump blood throughout the body.

Key Facts

• Pulmonary arterial hypertension (PAH) is a rare, progressive disorder (meaning it gets worse over time), in which the cause is usually unknown.
• PAH is most common in women between the ages of 30-60. 
• There is no cure for PAH, but treatments are available to control symptoms and improve quality of life.
• PAH is referred to as Group 1: PAH among the five types of pulmonary hypertension.
• PAH is a rare condition, with about 500-1000 new cases being diagnosed each year in the U.S. About 15-20% of patients with PAH have inherited the condition. 

What Causes Pulmonary Arterial Hypertension?

The exact cause of PAH is unknown. It is unlike other forms of pulmonary hypertension, where high blood pressure in the lungs is caused by underlying heart or lung disease. Researchers believe that PAH occurs when there is injury to the cells that line the blood vessels of the lung, which over time results in this blood vessel disease. If the cause of this change is unknown it is referred to as idiopathic PAH. If the change is believed to be caused by a genetic mutation it is called heritable PAH. Approximately 15-20% of PAH patients have heritable PAH.

Other conditions that are associated with the development of PAH include: connective tissue disorders like scleroderma and lupus; exposure to certain toxins and drugs, including methamphetamine and cocaine; infections, including HIV and schistosomiasis; cirrhosis of the liver; and congenital heart abnormalities.

Who Is at Risk?

Pulmonary arterial hypertension is more frequent in women between the ages of 30 and 60. Since there is an inherited form of PAH, a family history of the disease may put you at increased risk.