The cause of sarcoidosis isn't known. More than one factor may play a role in causing the disease.
Some researchers think that sarcoidosis develops if your immune system responds to a trigger, such as bacteria, viruses, dust, or chemicals.
Normally, your immune system defends your body against foreign or harmful substances. For example, it sends special cells to protect organs that are in danger.
These cells release chemicals that recruit other cells to isolate and destroy the harmful substance. Inflammation occurs during this process. Once the harmful substance is gone, the cells and the inflammation go away.
In people who have sarcoidosis, the inflammation doesn't go away. Instead, some of the immune system cells cluster to form lumps called granulomas in various organs in your body.
Genetics also may play a role in sarcoidosis. Researchers believe that sarcoidosis occurs if:
- You have a certain gene or genes that raise your risk for the disease
- You're exposed to something that triggers your immune system
Triggers may vary depending on your genetic makeup. Certain genes may influence which organs are affected and the severity of your symptoms.
Researchers continue to try to pinpoint the genes that are linked to sarcoidosis.
Living With and Managing Sarcoidosis05/18/2011
This video—presented by the National Heart, Lung, and Blood Institute, part of the National Institutes of Health—shows how Romaine, an executive and wife, has coped with having sarcoidosis. Although she had no symptoms, Romaine learned she had sarcoidosis of the lung as the result of testing done for another reason.
Prior to being diagnosed with sarcoidosis, Romaine had never heard of the disease. Within about 5 years of her diagnosis, she began having symptoms. Her symptoms started with a dry cough, which became chronic about a year after it first developed.
Unable to speak a sentence without coughing, Romaine began taking medicine to treat her sarcoidosis. Also, she began to focus on following a healthy lifestyle, including eating well and being physically active. By following her treatment plan and making lifestyle changes, Romaine is able to live a full, active life.
For more information about living with and managing sarcoidosis, go to the Health Topics Sarcoidosis article.