HIV, or human immunodeficiency virus, is a virus that attacks the immune system by destroying T cells. When HIV destroys so many T cells that the body can no longer protect itself against diseases, it leads to AIDS, or acquired immunodeficiency syndrome, states the Centers for Disease Control and Prevention.
As of 2015, there is no cure for HIV, according to the CDC; however, doctors can control HIV with treatment. Antiretroviral therapy, or ART, can dramatically lengthen the lifespan of HIV-infected patients and reduce their risk of infecting others. Early treatment is crucial; HIV patients who begin ART before the disease reaches advanced stages have a normal life expectancy. Before the advent of ART in the early 1990s, HIV patients typically progressed to full-blown AIDS in only a few years. Without proper medical treatment, HIV is nearly always fatal.
The only way that a person can tell if he is infected with HIV is to undergo an HIV test, which involves taking either a blood or saliva sample, notes the CDC. Many people infected with HIV experience no symptoms for up to 10 years. Symptoms of HIV infection that may occur two to four weeks after infection include fever, sore throat, rash and enlarged lymph nodes.