Autoimmune hepatitis occurs when the body's immune system, which ordinarily attacks viruses, bacteria and other pathogens, instead targets the liver. This attack on your liver can lead to chronic inflammation and serious damage to liver cells. Just why the body turns against itself is unclear, but researchers think autoimmune hepatitis could be caused by an interaction between several risk factors, such as infections, medications and a genetic predisposition.

Types of autoimmune hepatitis
Doctors have identified two main forms of autoimmune hepatitis:

- Type 1 (classic) autoimmune hepatitis. Often developing suddenly, this is the most common type of the disease. It can occur at any age. About half the people with type 1 autoimmune hepatitis have other autoimmune disorders, such as thyroiditis, rheumatoid arthritis or ulcerative colitis.

- Type 2 autoimmune hepatitis. Although adults can develop type 2 autoimmune hepatitis, it's most common in young girls and often occurs with other autoimmune problems.