Autoimmune hepatitis is a chronic inflammatory autoimmune disease of the liver. It usually occurs by itself, but it can coexist with other autoimmune diseases. The male/female ratio is 8:1, and it most often occurs in persons of Northern European extraction. It is usually classified as Type I or Type II. Type I is the most common and occurs at any age, most commonly in women. Type II is less common, affecting mostly girls between the ages of two to fourteen, although adults can have it too.