There are more than 80 types of autoimmune diseases, including:
These disorders occur when your immune cells mistake your body's cells as invaders and attack them.
What causes an autoimmune disease? Most researchers believe that there is a link between autoimmune diseases, a person's genes, and factors in the environment. Many experts believe that if you have a certain gene or combination of genes, you may be at higher risk for autoimmune disease but that you won't get the disease until something triggers your immune system, such as the sun, infections, drugs, or pregnancy.
Diagnosing an autoimmune disease can be difficult because most do not have a clear pattern of symptoms. In many cases, the first signs are fatigue, muscle aches, and low fever. However, autoimmune diseases can affect almost any organ or body system.
(To learn more, click Autoimmune Diseases. This full-length article offers details on topics such as how they are diagnosed, challenges that come with living with one of these disorders, and goals of treatment.)