The liver fights infections and stops bleeding. It removes drugs and other poisons from your blood. The liver also stores energy for when you need it. Hepatitis B is caused by a virus. A virus is a germ that causes sickness.
People can pass viruses to each other.
The virus that causes hepatitis B is called the hepatitis B virus. Hepatitis B spreads by contact with an infected person's blood, semen, or other body fluid. You could get hepatitis B by Having sex with an infected person without using a condom. Sharing drug needles. Getting a tattoo or body piercing with dirty tools that were used on someone else.