Sarcoidosis is a disease that leads to inflammation, usually in the lungs, skin or lymph nodes. It starts as tiny, grain-like lumps, called granulomas. Sarcoidosis can affect any organ in your body, and no one is sure what causes it. The condition can affect men and women of all ages and races and occurs mostly in people ages 20 to 50, African Americans, especially women and people of Northern European decent. Many people have no symptoms, however some indications may include: cough, shortness of breath, unexplained weight loss, night sweats and fatigue. Tests to diagnose sarcoidosis include chest x-rays, lung function tests and a biopsy. Not all sarcoidosis requires treatment, however the most common treatment prescribed is the use of a type of steroid called prednisone.