Hepatitis B is an infectious disease caused by the hepatitis B virus (HBV). It affects the liver, causing inflammation and tissue damage. The virus is spread through contact with the blood or body fluids of an infected person. It can also be spread from an infected mother to her baby during childbirth. The most common symptom of hepatitis B is jaundice, which is a yellowing of the skin and eyes. Other symptoms may include fatigue, nausea, loss of appetite, and abdominal pain. In some cases, there are no symptoms at all. In more severe cases, hepatitis B can cause liver failure, cirrhosis, and even death. There is a vaccine available to prevent hepatitis B. It is recommended for all infants and children, and for adults who are at risk of infection. Treatment for hepatitis B includes antiviral medications, which can help reduce symptoms and prevent the virus from becoming active again. Hepatitis B can be a serious and life-threatening illness, but it can be prevented. Vaccination, safe sexual practices, and avoiding contact with the blood and body fluids of infected people are all important steps to help protect yourself from hepatitis B.