The cause of premature ovarian failure is generally unknown. However, there are a few reasons why the ovaries may experience a decrease in egg supply at an early age. Exposure to certain chemicals or medical treatments can damage or destroy the ovaries. These may include chemotherapy and radiation therapy. Autoimmune diseases, such as rheumatoid arthritis, are sometimes associated with early menopause, because the immune system forms antibodies that attack and damage the ovaries. Heredity can also play a role as some genetic disorders lead to early menopause. Women with premature ovarian failure are also more likely to have thyroid disease and diabetes.