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The Difference Between HIV and AIDS

HIV is the virus that can become AIDS.

AIDS is defined as the most advanced stage of the virus, where the immune system has become so damaged that you're vulnerable to infection and cancers that come from infections. Those are called opportunistic illnesses, because they take advantage of your weakened immune system. They are often fatal.

When Does HIV Become AIDS?

HIV stands for human immunodeficiency virus. AIDS stands for acquired immunodeficiency syndrome.

The HIV virus destroys white blood cells, which fight off infection. Those cells are called CD4 cells, or T cells. If you have HIV, virus levels increase in your blood, while the number of CD4 cells goes down.

Once you've been diagnosed with AIDS, you're always considered to have AIDS, even if your CD4 count goes up again.

Medicines Can Make All the Difference

People with HIV can take medication to suppress the virus and keep it from becoming AIDS. These meds are called antiretroviral drugs. Doctors will usually prescribe three or more of them, which must be taken daily. This is referred to as antiretroviral therapy, or ART.

Thirty-one antiretroviral drugs have been approved by the FDA to treat HIV infection. They don’t cure HIV -- it’s still in the blood reproducing, and the person can still pass the virus to others. But on ART, people with HIV can, in many cases, suppress the virus until it is considered undetectable, meaning the virus can no longer be found in the blood. As a result they can enjoy a high quality of life.

The period of time before a person with HIV develops symptoms is called clinical latency, inactivity, or dormancy. For people on ART, this period of low viral activity can last for decades. Those not on ART might enjoy a low-activity period of10 years, though it will be less in some cases.

Taking ART early is key to keeping HIV from becoming AIDS, which is far more dangerous. Your doctor will monitor your CD4 count, and together you can decide when it’s time.

AIDS Incidence Dropping

About 1.1 million people in the United States were living with HIV at the end of 2009, the most recent year the data was available. It’s estimated that 18% don’t know they’re infected.

In 2010, 15,500 people in the U.S. died from AIDS. That number was a sharp drop from previous years, as new medicines have become available to suppress the virus in people with HIV -- and to help them live healthier, more active, and often longer lives.

WebMD Medical Reference

Reviewed by David T. Derrer, MD on December 03, 2013

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