What does HIV do when it isn’t treated?
HIV disease has a well-documented progression. If you are infected with HIV and don’t get treatment, HIV will eventually overwhelm your immune system—and this will lead to your being diagnosed with Acquired Immune Deficiency Syndrome (AIDS).
Here’s what typically happens:
- Acute Infection: Within 2-4 weeks after infection with HIV, you can experience an acute illness, which is often described as “the worst flu ever.” This is called acute retroviral syndrome (ARS) or primary HIV infection and it’s the body’s natural response to the HIV infection. (Not everyone develops ARS, however—and it can take up to 3 months for it to appear in some people who do.)
During this period of infection, large amounts of virus are being produced in your body. The virus uses CD4 cells to replicate and destroys them in the process. Because of this the CD4 count can fall rapidly. Eventually your immune response will begin to bring the level of virus in your body back down to a level called a viral set point, which is a relatively stable level of virus in your body. At this point, your CD4 count begins to increase, but it may not return to pre-infection levels.
For more information, see NIH’s Acute HIV infection.
- Clinical Latency: After the acute stage of HIV infection, the disease moves into a stage called clinical latency. This period is sometimes called asymptomatic HIV infection or chronic HIV infection. During this phase, HIV reproduces at very low levels, although it is still active. You may be able to maintain an undetectable viral load and a healthy CD4 cell count without the use of medication during the earlier years of this phase. You may not have symptoms or opportunistic infections. This period can last up to 8 years or longer.
Some people progress through this phase faster than others. It is important to remember that you are still able to transmit HIV to others during this phase.
Toward the middle and end of this period, your viral load begins to rise and your CD4 cell count begins to drop. As this happens, you may begin to have constitutional symptoms of HIV as the virus levels increase in your body.
- AIDS: As the number of your CD4 cells begins to fall below 200 cells per cubic millimeter of blood (200 cells/mm3), you will be diagnosed as having AIDS. (Normal CD4 counts are between 500 and 1,600 cells/mm3.) This is the stage of infection that occurs when your immune system is badly damaged and you become vulnerable to opportunistic infections. Without treatment, people who are diagnosed with AIDS typically survive about 3 years. Once someone has a dangerous opportunistic infection, life-expectancy falls to about 1 year.
- National Institute of Allergy and Infectious Diseases - HIV/AIDS: How HIV Causes AIDS
Last revised: 08/06/2009