
Autoimmune diseases result when the immune system mistakenly attacks its own body’s tissues. Immune deficiency is more common than most people think; around 20 percent of the population suffers from some form of an autoimmune disorder, according to the American Autoimmune Related Diseases Association.
Although symptoms vary greatly depending on the specific disease, commons symptoms include chronic fatigue, joint pain, muscle weakness, weight loss, dry eyes, and abdominal pain.