Sarcoidosis occurs in all age groups but mainly affects people in their late 20's to early 40's. Approximately 1 in 10,000 people have it. It occurs more commonly in some families. A genetic predisposition to the development of Sarcoidosis is suspected. The incidence of disease differs in some races, being more common in blacks than Caucasians and unusual in those of Asian descent and Australian Aborigines.
Sarcoidosis can affect any part of the body.
Swollen lymph glands inside the chest or shadows on the lungs are often an unexpected finding when a routine chest x-ray has been taken for some other reason. Sometimes swollen glands are present elsewhere, such as in the neck. Some people develop red tender lumps on their shins known as erythema nodosum. Sarcoidosis may also affect the eyes, liver, kidneys, heart and brain. Many persons with the disease have no symptoms, or common symptoms when present include breathlessness with exertion, tiredness, cough or chest discomfort.