Human immunodeficiency virus (HIV)

Human immunodeficiency virus (HIV) is a virus that attacks the body's immune system, specifically the CD4 cells, often referred to as T cells. Over time, HIV can destroy so many of these cells that the body can't fight off infections and disease. This damage to the immune system makes it harder for the body to fight off infections and some other diseases. Opportunistic infections or cancers take advantage of a very weak immune system and signal that the person has AIDS.

Transmission

HIV is transmitted through direct contact with certain body fluids from a person who has HIV. These body fluids include blood, semen, vaginal fluids, and breast milk. In the United States, HIV is spread mainly by having sex or sharing drug injection equipment with someone who has HIV.

Symptoms

The symptoms of HIV and AIDS vary, depending on the phase of infection. When first infected with HIV, you may have no symptoms at all, although it's more common to develop a brief flu-like illness two to four weeks after becoming infected. But because the signs and symptoms of an initial infection — a fever, headache, sore throat, swollen lymph nodes and rash — are similar to those of other diseases, you might not realize you've been infected with HIV.

Prevention

Prevention of HIV involves practicing safer sex (such as using condoms), getting regular testing, and being in a treatment program for drug use if that is a factor. Pre-exposure prophylaxis (PrEP) is also an option for people at high risk of getting HIV.

Treatment

While there is no cure for HIV, with early diagnosis and treatment, the virus can be controlled and a person with HIV can live a long and healthy life. Antiretroviral therapy (ART) is used to treat HIV.