An inflammation of the liver causing soreness and swelling. It is the most common chronic blood-borne infection in the United States. The hepatitis C virus usually is transmitted through contact with infected blood, most commonly by sharing needles during intravenous drug use, or getting a blood transfusion before 1992. Hepatitis C also may be spread through unprotected sexual intercourse, but this is uncommon. Most people don’t feel sick when they are first infected with hepatitis C. Instead, the virus stays in their liver and causes chronic liver inflammation.