The hepatitis C virus was discovered in 1989. Since then, we've learned a lot about it. We now know how people get it, and how it affects their bodies.
Hepatitis C is spread mostly through infected blood and blood products. Before 1990, there was no way to test for the virus when people donated blood. So, some people were infected when they had a blood transfusion. But because we can now test donated blood before it's used, it is extremely rare for people to get hepatitis C from blood transfusions.
Today, most people get hepatitis C from infected blood, whether it's from working in a laboratory or a dialysis unit, by infected needles used for tattoos or body piercing, or through sharing drug needles. In a very few cases, people have gotten hepatitis C from sharing objects that may have a very tiny amount of blood on them, such as a toothbrush, razor, or tools used for manicures.
Hepatitis C can also be spread by sexual intercourse, but this is rare. For steady sexual partners, there aren't any recommendations about changing your sexual practices just because you or your partner has hepatitis C. But, having more than one sex partner does increase your chance of getting the virus.
Hepatitis C is NOT spread through normal, everyday activities. Things like sitting next to a person with the virus, shaking hands, hugging, kissing, or even sharing eating utensils won't infect you.
Though we know the ways that hepatitis C can be spread, some people are never able to figure out exactly how they got the infection.