Autoimmunity refers to a failing of the immune system to differentiate between the body’s own tissues and invading bodies.

A person’s gender is thought to play a role in the development of autoimmunity, with most autoimmune conditions being related to gender.

Studies have shown that around three quarters of Americans who have autoimmune illnesses are female, although millions of men do also develop the conditions.

According to estimates from the American Autoimmune Related Diseases Association, when autoimmune diseases are seen in males, they tend to be more severe than those observed in women. Some examples of autoimmune conditions men are equally likely to develop include type 1 diabetes mellitus, ankylosing spondylitis, psoriasis, Crohn’s disease, and Wegener’s granulomatosis.

Why women are more likely to suffer from the other types of autoimmune disease is not clear. Women generally seem to mount more intense inflammatory responses then men when their immune systems are stimulated, which increases the likelihood of autoimmunity developing. Sex hormones are thought to be involved because studies suggest a correlation between fluctuating hormones and degrees of autoimmunity during pregnancy or the menstrual cycle, for example. Pregnancy also seems to increase the risk of autoimmunity developing, possibly due to cell exchange that occurs between mother and baby during gestation.