Stages of HIV infection
The U.S. Centers for Disease Control and Prevention (CDC) classify HIV infection into four stages.1
Stages of HIV infection
- Stage 1: There are no AIDS-related conditions AND the CD4+ cell count is greater than 500 or the percent of CD4+ cells is at least 29% of all lymphocytes.
- Stage 2: There are no AIDS-related conditions AND the CD4+ cell count is 200 to 499 or the percent of CD4+ cells is 14% to 28% of all lymphocytes.
- Stage 3: The CD4+ cell count is lower than 200, the percent of CD4+ cells is less than 14% of all lymphocytes, or an AIDS-related condition is present.
- Stage unknown: No information is available on the CD4+ cell count or the presence of AIDS-related conditions.
In general, the higher the CD4+ count, the less likely it is that opportunistic diseases will occur. Most people who have untreated HIV experience a gradual drop in the number of CD4+ cells. Each person responds uniquely to this decline.
| Author: | Maria G. Essig, MS, ELS | Last Updated: April 10, 2009 |
| Medical Review: | Caroline S. Rhoads, MD - Internal Medicine Peter Shalit, MD, PhD - Internal Medicine | |
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