The very basics about HIV and AIDS

How does HIV spread?

Human immunodeficiency virus, or HIV, is most commonly transmitted through anal or vaginal sex or through sharing drug injection equipment with a person who is infected with HIV.  A mother can also pass HIV to her baby during pregnancy, labor, or breastfeeding. It is possible to get HIV through contact with contaminated blood or body fluids that enter through broken skin, your eyes, nose or mouth, or from needles. Once a person gets HIV, he/she has it for life because the body cannot get rid of the virus.

How does HIV impact people’s health?

HIV attacks CD4 cells in your body. These cells are part of your immune system, which helps to keep you healthy. With time, HIV can destroy so many cells in your body that it can no longer fight infections or diseases. When this happens, HIV leads to acquired immunodeficiency syndrome, also called AIDS.

What is the difference between HIV and AIDS?

The difference between AIDS and HIV is that a person is said to have AIDS—as opposed to simply being HIV positive—when either the numbers of CD4 cells in his/her immune system drop below a certain level or when the person develops one of a specific group of opportunistic infections.

Can HIV be controlled?

Yes, with proper medical care, HIV can be controlled. Treatments called antiretroviral therapy, or ART, can lower the chance of HIV progressing to AIDS. But left untreated, HIV is almost always fatal.

What happens when someone gets HIV?

There are several stages of HIV.

  • In the acute stage, within 2 to 4 weeks after infection with HIV, you may start to feel sick with flu-like symptoms such as fever, sore throat, rash, and/or enlarged lymph nodes. During this time, large amounts of HIV are being produced in your body.  
  • During the dormant or inactive stage, HIV is still active but reproduces at very low levels. You may not feel sick at all. If you are taking ART, you can stay this way for many years.  It is important to remember that you are still able to transmit HIV to others during this period.
  • AIDS (acquired immunodeficiency syndrome) is the stage of infection that happens when your body’s immune system is badly damaged and you are vulnerable to other infections, called opportunistic illnesses. Examples of opportunistic infections include Kaposi’s sarcoma, Pneumocystis, and Mycobacterium. People with AIDS need medical treatment to prevent death.

It is very important to know if you have HIV. Approximately 1.1 million people in the United States are living with HIV, and 17 million are infected worldwide.  By knowing, you can begin to take medication to keep you healthy. You can protect your sex partners. You can also protect your needle-sharing partners.

How can I find out if I have HIV?

The only way to know if you have HIV is to get tested. You can do this in several ways:

  • Ask your doctor for a test
  • Find a place to get tested in your community.  To locate an HIV testing site near you, go to, call 1-800-CDC-INFO or text your zip code to “KNOW IT” (566948).
  • Ask your local health department.
  • Use home-testing kits available at many drugstores.

Additional resources
National Institutes of Health—AIDS info
APIC consumer alert—World AIDS Day: “The time to act is now.”