Hepatitis C is caused by the hepatitis C virus, which spreads through contact with an infected person's blood. Contact can occur in a number of ways, including:

  • Sharing drug needles or other drug materials with an infected person
  • Getting an accidental stick with a needle that was used on an infected person
  • Being tattooed or pierced with tools that were used on an infected person and were not properly sterilized, or cleaned in a way that destroys all viruses and other microorganisms
  • Having contact with the blood or open sores of an infected person
  • Using an infected person's razor, toothbrush, or nail clippers
  • Being born to a mother with hepatitis C
  • Having unprotected sex with an infected person, though sexual transmission is actually quite rare with hepatitis C

Certain behaviors and situations can increase the risk of being infected with hepatitis C, including:

  • Using injectable drugs
  • Having had a blood transfusion or organ transplant before July, 1992
  • Having hemophilia and having received a clotting factor before 1987
  • Being on kidney dialysis
  • Working in a field, such as healthcare, in which there is regular contact with blood or infected needles
  • Getting tattoos or body piercings
  • Working or living in a prison
  • Being born to a mother with hepatitis C
  • Being infected with HIV
  • Having more than one sex partner in six months
  • Having a history of sexually transmitted infections
  • Men having sex with other men

Baby boomers, or people born between 1945 and 1965*, constitute about 75 percent of adults with hepatitis C in the United States, but the number of people under 30 being diagnosed has been rising in recent years. The most common way the hepatitis C virus spreads in these groups is by using injectable drugs.

*It is highly recommended that anyone born between 1945 and 1965 be screened for hepatitis C.