HIV is an acronym for human immunodeficiency virus, the virus that causes AIDS, or acquired immune deficiency syndrome. The Centers for Disease Control and Prevention (CDC) report that the virus attacks the immune system, eventually leaving the body prone to multiple different types of infections. The CDC estimates that approximately 1.1 million people are currently living with HIV or AIDS. A person can be infected with HIV, but not yet have AIDS, because the virus has not yet severely weakened the immune system. The disease usually follows a five-stage progression.
AIDS.gov, a resource provided by the U.S. Department of Health and Human Services, reports that acute infection occurs within two to four weeks after infection with HIV. The symptoms of the acute infection are similar to a bad flu or, as AIDS.gov describes it, "the worst flu ever." During the acute infection phase, AIDS.gov reports that large amounts of virus are being produced in the body, attacking CD4 T cells, which are one type of cell that makes up the immune system. Eventually the body brings the virus back down to low levels, and the CD4 T cell count increases.
The next stage of HIV infection is clinical latency, a period that may extend for several years, where the infected person feels no symptoms. Thebody.com, an online HIV/AIDS resource, reports that often the only clue that a person is infected with HIV is that he would test positive in an HIV test. Additionally, he may have larger-than-normal lymph nodes. AIDS.gov reports that this stage can persist for a period of eight years or longer.
Early Stage AIDS
Early stage AIDS occurs when the body's immune system is compromised enough to be susceptible to some mild bacterial, viral and fungal infections. In early stages of AIDS, thebody.com reports that the person may experience mild symptoms such as skin rashes, fatigue, night sweats, slight weight loss and fungal skin and nail infections. The National Institute of Allergy and Infectious Diseases (NIAID) reports that headache and fatigue are also common symptoms of early stage AIDS.
The middle stage of AIDS is characterized, according to thebody.com, as an increase in severity of infections. The person may experience troublesome fungal infections of the mouth or vagina called thrush, which manifests as a white or yellow film that may cause irritation. Thebody.com reports that other symptoms characteristic of middle-stage AIDS include: herpes infection of the mouth and genitals (cold sores), diarrhea, more dramatic weight loss and persistent fevers.
In late-stage AIDS, infections may make the infected person consistently and often severely sick. Thebody.com reports that these infections include Mycobacterium avium complex disease (caused by a fungus) Pneumocystis carinii pneumonia (caused by a bacteria), and cytomegalovirus (caused by a virus). The NIAID reports that chronic severe diarrhea, intense night sweats, memory loss, depression and other disorders of the brain may occur in late-stage AIDS. Furthermore, the person may develop type of cancer called Kaposi's sarcoma that causes red, brown or purple blotches on the skin of the face.