Blood work:
Two common tests to use for
monitoring HIV disease

January 2008     View PDF     En español

Why do you use CD4 cell counts?

CD4 cell counts tell you how many of these cells are present but not how they function. Using CD4 counts along with viral load tests and information about your general health provides a more complete picture of your health and response to therapy. It also is the best way to foresee problems that are developing from HIV disease. CD4 cell counts are the best guide for when to start preventive therapy for opportunistic infections, or OIs.

CD4 cell counts may vary and do not fully define your level of health or illness. Tests can vary due to the time of day, an active infection, lack of sleep, stress and other factors. Variations in the lab that’s used, as well as how quickly the test is done after your blood is drawn, can also affect test results. Therefore, it’s important to look at your CD4 cell count trends over time and not be alarmed by any one test result.