Sarcoidosis is the growth of tiny collections of inflammatory cells in different parts of your body — most commonly the lungs, lymph nodes, eyes and skin.
Doctors believe sarcoidosis results from the body's immune system responding to an unknown substance, most likely something inhaled from the air. There is no cure for sarcoidosis, but most people do very well with modest treatment. Sarcoidosis often goes away on its own. Alternatively, signs and symptoms of sarcoidosis may last for years and sometimes lead to organ damage.