Hepatitis is inflammation of the liver. It is most commonly caused by a viral infection, but may be due to chemicals, alcohol or drugs and inherited diseases or autoimmune disease. This page will deal only with those caused by viruses.
The liver performs many functions in the body, including processing the body’s nutrients, manufacturing bile to help digest fats, and breaking down potentially toxic (harmful) substances into harmless ones that the body can use or excrete. When the liver is damaged, these functions are impaired to some extent and the potentially toxic substances accumulate. The hepatitis virus reaches the liver through the blood stream, multiplies in the liver cells, and is released into the bloodstream, the bile duct, and faeces; in this way, it can be spread to other people.
The accompanying table summarises the three most common strains of hepatitis: Hepatitis A, Hepatitis B, and Hepatitis C.