Hepatitis C is a liver infection caused by the hepatitis C virus (HCV). Hepatitis C is a blood-borne virus. Today, most people become infected with the hepatitis C virus by sharing needles or other equipment to inject drugs. For some people, hepatitis C is a short-term illness but for 70%–85% of people who become infected with the hepatitis C virus, it becomes a long-term, chronic infection. Chronic hepatitis C is a serious disease than can result in long-term health problems, even death. Many people might not be aware of their infection because they are not clinically ill. There is no vaccine for hepatitis C. The best way to prevent hepatitis C is by avoiding behaviors that can spread the disease, especially injecting drugs.