• Topic Overview
• Related Information
• References
• Credits

Topic Overview

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.

Related Information

• Human Immunodeficiency Virus (HIV) Infection
• Risk Factors for HIV Infection

References

Credits