An autoimmune disorder occurs when the immune system attacks the body itself, rather than disease-causing germs such as bacteria and viruses.
The U.S. National Institute of Arthritis and Musculoskeletal and Skin Diseases says symptoms of an autoimmune disorder typically include:
- Joint pain and stiffness.
- Thyroid problems, which cause you to feel tired, gain weight and have muscle aches.
- Skin issues, such as rashes, blisters and color changes.