By Dr Ananya Mandal, MD
Hepatitis B does not usually cause symptoms, with most people remaining well while they fight off the infection.
In cases where symptoms do develop, they occur between 40 and 160 days after infection and tend to pass within three months. This is referred to as an acute infection and the symptoms include:
- Flu-like symptoms such as weakness, aches, headaches, and a temperature of 38ºC (100.4ºF) or above
- Loss of appetite
- Nausea and vomiting
In around 1 in 20 affected adults, the infection is not acute but chronic and stays in the body for six months or more. This chronic form of hepatitis B is very common in young infants and children. About 90% of infants who are infected as newborns and 20% of young children affected go on to develop chronic infection. Even if these children do not have symptoms, they can still pass the infection onto other people.
The symptoms of chronic hepatitis B tend to be much milder and are often absent altogether. However, if the condition is left untreated, serious complications can develop.
About 20% of people who develop long-term infection will develop liver disease and suffer from scarring or cirrhosis of the liver and around 10% of those who develop cirrhosis will go on to develop liver cancer.
Reviewed by Sally Robertson, BSc
Last Updated: Aug 12, 2014