As mentioned above, hepatitis B is an STD (sexually transmitted disease) caused by hepatitis B virus. The virus is transmitted when a person gets into contact with infected blood, semen among other body fluids. The disease causes the liver to swell. Patients can also get liver infections which progress to cancer. Hepatitis B is chronic for many. It can persist for years, sometimes for a lifetime. The risks of getting Hepatitis B are higher among individuals who have unprotected sex as well as those who use unsterilized needles. Newborns can also contract Hepatitis B from infected mothers during birth.