Sarcoidosis is an inflammatory disease that affects multiple organs in the body, but mostly the lungs and lymph glands. In people with sarcoidosis, abnormal masses or nodules (called granulomas) consisting of inflamed tissues form in certain organs of the body. These granulomas may alter the normal structure and possibly the function of the affected organ(s).
The symptoms of sarcoidosis can vary greatly, depending on which organs are involved. Most patients initially complain of a persistent dry cough, fatigue, and shortness of breath. Other symptoms may include:
In some people, symptoms may begin suddenly and/or severely and subside in a short period of time. Others may have no outward symptoms at all even though organs are affected. Still others may have symptoms that appear slowly and subtly, but which last or recur over a long time span.
Sarcoidosis most often occurs between 20 and 40 years of age, with women being diagnosed more frequently than men. The disease is 10 to 17 times more common in African-Americans than in Caucasians. People of Scandinavian, German, Irish, or Puerto Rican origin are also more prone to the disease. It is estimated that up to four in 10,000 people in the U.S. have sarcoidosis.
The exact cause of sarcoidosis is not known. It is a type of autoimmune disease associated with an abnormal immune response, but what triggers this response is uncertain. How sarcoidosis spreads from one part of the body to another is still being studied.