Sarcoidosis (from sarc meaning flesh, -oid, like, and -osis, diseased or abnormal condition), also called sarcoid, Besnier-Boeck disease or Besnier-Boeck-Schaumann disease, is a disease in which abnormal collections of chronic inflammatory cells (granulomas) form as nodules in multiple organs.

The cause of sarcoidosis is unknown. Granulomas most often appear in the lungs or the lymph nodes, but virtually any organ can be affected. Normally the onset is gradual. Sarcoidosis may be asymptomatic or chronic.

It commonly improves or clears up spontaneously. More than 2/3 of people with lung sarcoidosis have no symptoms after 9 years. About 50% have relapses. About 10% develop serious disability. Lung scarring or infection may lead to respiratory failure and death.Chronic patients may deal with waxing and waning symptoms over many years.

Sarcoidosis is a disease that results from a specific type of inflammation of tissues of the body. It can appear in almost any body organ, but it starts most often in the lungs or lymph nodes. The cause of sarcoidosis is unknown.

The disease can appear suddenly and disappear. Or it can develop gradually and go on to produce symptoms that come and go, sometimes for a lifetime.