The Epstein-Barr Virus IgG test is a blood test used to measure the levels of IgG antibodies directed against the Epstein-Barr virus. This test helps determine whether an individual has been exposed to the virus in the past, which assists in evaluating their immune status. The Epstein-Barr virus is responsible for several diseases, including infectious mononucleosis. By measuring antibody levels, doctors can provide insights into the history of the infection and guide appropriate treatment options if necessary.