Hepatitis C is an infection of the liver caused by the hepatitis C virus.
It can cause inflammation and scarring of the liver tissue, and sometimes significant liver damage.
Many people do not realise they have been infected with the virus because they may not have any symptoms, or they may have flu-like symptoms that can easily be mistaken for another illness.
You can become infected with hepatitis C if you come into contact with the blood or, less commonly, body fluids of an infected person.
Drug users sharing needles are at particular risk. The hepatitis C virus is present in the blood and, to a much lesser extent, the saliva and semen or vaginal fluid of an infected person.
It's particularly concentrated in the blood, so it is usually transmitted through blood-to-blood contact.
Tests and treatment
If you think you may have been exposed to hepatitis C, taking a blood test will put your mind at rest, or (if the test is positive) enable you to start treatment early. You can ask your GP or sexual health clinic for more information.
The course of hepatitis C is unpredictable. About one in five people with hepatitis C will fight the infection and naturally clear it from their bodies within two to six months, experiencing no long-term effects.
Of the rest, some will remain well and never develop liver damage, but many will develop mild to moderate liver damage (with or without symptoms). In a few people, their liver damage will progress to cirrhosis (severe scarring of the liver) over 20-30 years, which can lead to liver failure.
Treatment with interferon and ribavirin can clear the infection in approximately half of those who are infected, but there are significant side effects
There is currently no vaccine to prevent hepatitis C.