Definition of Sarcoidosis

Sarcoidosis is a disease in which swelling (inflammation) occurs in the lymph nodes, lungs, liver, eyes, skin, or other tissues.

Causes, incidence, and risk factors

The cause of the disease is unknown. In sarcoidosis, clumps of abnnormal tissue (granulomas) form in certain organs of the body. Granulomas are clusters of immune cells.


There may be no symptoms. When symptoms occur, they can involve almost any part or organ system in your body.

Signs and tests

Often the disease is found in patients with no symptoms who have an abnormal chest x-ray.


Sarcoidosis symptoms often get better on their own gradually without treatment.

Expectations (prognosis)

Many people are not seriously ill, and the disease may get better without treatment. About 30 – 50% of cases get better without treatment in 3 years. About 20% of those whose lungs are involved will develop lung damage.


Allen J. Blaivas, D.O., Division of Pulmonary and Critical Care Medicine, UMDNJ-New Jersey Medical School, Newark, NJ. Review provided by VeriMed Healthcare Network. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc. – 5/21/2009

Sarcoid, stage I - chest X-ray
Sarcoid, stage II - chest X-ray
Sarcoid, stage IV - chest X-ray
Sarcoid - close-up of the skin lesions
Erythema nodosum associated with sarcoidosis
Sarcoidosis - close-up
Sarcoidosis on the elbow
Sarcoidosis on the nose and forehead
Respiratory system

ADAM Medical Encyclopedia

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