The liver is your largest internal organ. About the size of a football, it's located mainly in the upper right portion of your abdomen, beneath the diaphragm and above your stomach, but a small portion extends into the upper left quadrant. Parasites and viruses can infect the liver, causing inflammation. Subsequently, this can lead to a reduction or disruption of liver function. The viruses that cause liver damage can be spread by blood or semen, contaminated food or water, or close contact with a person who is infected.