“Sarcoidosis is an illness that causes tiny islands of inflammatory cells to form throughout the body. These microscopic groups of cells are called granulomas. They are especially common in the lungs, lymph nodes, skin, eyes, and liver. The cause of sarcoidosis is unknown.

Sometimes these granulomas cause very little damage, so a person with sarcoidosis does not have any symptoms of illness and may not even know they have it. In other cases, however, the granulomas produce large areas of inflammation and scarring that can interfere with an organ’s normal functions.”

Harvard Health (Sarcoidosis – Harvard Health)