Hepatitis B is an infection of your liver. It can cause scarring of the organ, liver failure, and cancer. It can be fatal if it isn’t treated.

It’s spread when people come in contact with the blood, open sores, or body fluids of someone who has the hepatitis B virus.

It's serious, but if you get the disease as an adult, it shouldn’t last a long time. Your body fights it off within a few months, and you’re immune for the rest of your life. That means you can't get it again. But if you get it at birth, it’ unlikely to go away.

The most common ways to get hepatitis B include:

Sex. You can get it if you have unprotected sex with someone who has it and your partner’s blood, saliva, semen, or vaginal secretions enter your body. Sharing needles. The virus spreads easily via needles and syringes contaminated with infected blood. Accidental needle sticks. Health care workers and anyone else who comes in contact with human blood can get it this way. Mother to child. Pregnant women with hepatitis B can pass it to their babies during childbirth. But there’s a vaccine to prevent newborns from becoming infected.