Causes of sarcoidosis

We don’t know what causes sarcoidosis, but we do know it’s related to your immune system behaving in a way it shouldn’t. 

Normally your immune system fights infections by releasing white blood cells into your blood to destroy germs. This causes the affected part of your body to become inflamed, making it swollen or red.

Researchers think that sarcoidosis could be caused by something in the environment that stops your immune system working properly. Instead of attacking germs, it attacks healthy parts of your body.

Research also suggests that, for some people, the risk of getting sarcoidosis is related to their genes. Sometimes, more than one family member can get sarcoidosis. But there’s no evidence that it’s infectious.

Next: Symptoms of sarcoidosis >


If you have urgent concerns or need advice quickly, call our helpline on 03000 030 050 between 9am and 5pm on a weekday or email them.

Download our sarcoidosis information (247KB, PDF) Order your free sarcoidosis leaflet >

Last medically reviewed: January 2017. Due for review: January 2020

This information uses the best available medical evidence and was produced with the support of people living with lung conditions. Find out how we produce our information. If you’d like to see our references get in touch.