The word "hepatitis" means inflammation of the liver and also refers to a group of viral infections that affect the liver. The most common types are Hepatitis A, Hepatitis B, and Hepatitis C.

Viral hepatitis is the leading cause of liver cancer and the most common reason for liver transplantation. In the United States, an estimated 1.2 million Americans are living with chronic Hepatitis B and 3.2 are living with chronic Hepatitis C. Many do not know they are infected. Each year an estimated 25,000 persons become infected with Hepatitis A; 43,000 with Hepatitis B, and 17,000 with Hepatitis C.