is an inflammatory disease characterized by the development and growth of tiny lumps of cells called granulomas. If these tiny granulomas grow and clump together in an organ, they can affect how the organ works, leading to the symptoms of sarcoidosis. The granulomas can be found in almost any part of the body, but occur more commonly in the lungs, lymph nodes, eyes, skin, and liver. Although no one is sure what causes sarcoidosis, it is thought by most scientists to be a disorder of the immune system. The course of the disease varies from person to person. It often goes away on its own, but in some people symptoms of sarcoidosis may last a lifetime. For those who need treatment, anti-inflammatory medications can help. Source: Genetic and Rare Diseases Information Center (GARD), supported by ORDR-NCATS and NHGRI.