Causes

Your doctor will do some tests to confirm if you have PAH and look for a cause. It’s important to look for the underlying cause of PAH as it will help your doctor to provide the best treatment options and support.

Here are some of the things that can cause PAH:

• Genetics: PAH can sometimes run in families. If you have PAH or have a family history of it, it’s important for your close family members to get tested too.
• Drugs and toxins: PAH can sometimes be caused by exposure to certain drugs or chemicals. 
• Chronic thromboembolic pulmonary hypertension (CTEPH): This occurs when blood clots in the lungs don’t dissolve, causing a blockage and build up of pressure in the lungs.
• Other health problems: Sometimes, PAH is linked to other health problems, including:
  • Connective tissue diseases (like scleroderma, lupus, and rheumatoid arthritis). These conditions affect the body’s structural parts, such as joints and skin, but can also involve other organs
  • HIV infection
  • Congenital heart disease (heart problems you’re born with)
  • Liver disease, including cirrhosis.

Idiopathic: Sometimes, even after lots of tests, doctors can’t find a cause for PAH. When this happens, it’s called idiopathic PAH.

What’s the difference between PH and PAH?

You might hear these two acronyms and wonder what the difference is. 

• Pulmonary hypertension (PH): is a term used to describe high blood pressure in the lungs. It can be caused by several things including heart problems, lung diseases, sleep apnoea or blood clots.
• Pulmonary arterial hypertension (PAH): is a specific type of PH. It happens when disease affects the blood vessels leading to the lungs, which directly causes high blood pressure in the lungs.