Medical Dictionary: Sarcoidosis
Sarcoidosis is a condition where inflammatory cells to grow and collect in different parts of the body such as the lungs, lumph 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 like bacteria, viruses, dust or chemicals. Some people may have a genetic predisposition to developing the disease, but researchers are still trying to pinpoint the genes and trigger substances associated with sarcoidosis. Normally, the immune system helps protect your body from foreign substances and invading microorganisms, such as bacteria and viruses. But in sarcoidosis, some immune cells collect in a pattern of inflammation called granulomas. As granulomas build up in an organ, the function of that organ can be affected. Sometimes the condition develops gradually and produces symptoms that last for years. Other times, symptoms appear suddenly and then disappear just as quickly. Many people with sarcoidosis have no symptoms, so the disease may be discovered only by a chest X-ray. For many people, sarcoidosis signs begin with fatigue, fever, swollen lymph nodes and weight loss.
Source: The Mayo Clinic