Lupus is a chronic autoimmune disease in which the body's own immune system attacks healthy tissues. The condition affects about 1.5 million people and tends to strike women during their childbearing years.
The symptoms: Lupus often causes extreme fatigue, headaches, oral ulcers, and painful, swollen joints. Many people develop a butterfly-shaped rash across the bridge of the nose and become more sensitive to the sun.
Other symptoms include fever; swelling in the feet and hands and around the eyes; chest pain; and anemia. Many people also experience hair loss, which may be mild and occur while shampooing or brushing your hair—or it may be more severe, coming out in patches and accompanied by a rash on the scalp, says Arthur Weinstein, MD, director of the division of rheumatology at the Washington Hospital Center. Because these symptoms occur in many other conditions, lupus is often called the great imitator.