What causes pulmonary arterial hypertension?
Pulmonary arterial hypertension (PAH) happens when the small blood vessels in your lungs become narrow, thick, or stiff, making it harder for blood to flow through. This raises pressure in those arteries and forces your heart to work harder.
The exact causes aren't always Show Full Answer
What causes pulmonary arterial hypertension?
Pulmonary arterial hypertension (PAH) happens when the small blood vessels in your lungs become narrow, thick, or stiff, making it harder for blood to flow through. This raises pressure in those arteries and forces your heart to work harder.
The exact causes aren't always known, but several factors can lead to PAH:
Medical conditions that can cause PAH:
* Connective tissue disorders (like scleroderma or lupus)
* Congenital heart disease (heart problems present from birth)
* Liver disease
* HIV and other infections
* Blood cell disorders
Other causes:
* Inherited gene mutations (especially the BMPR2 gene)
* Certain prescription or illicit drugs
* Exposure to toxins
* Idiopathic causes (meaning no known reason)
About 30 percent of people with PAH have connective tissue disease. Interestingly, even if you have a genetic mutation linked to PAH, 80 percent of people with that mutation never develop the condition.
Researchers believe PAH usually develops when blood vessels are extra sensitive to certain factors that cause them to narrow, combined with genetic predisposition or other medical conditions.
December 15, 2025
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