Why do I need a CD4 count?
Your health care provider may order a CD4 count when you are first diagnosed with HIV. You will probably be tested again every few months to see if your counts have changed since your first test. If you are being treated for HIV, your health care provider may order regular CD4 counts to see how well your medicines are working.
Your provider may include other tests with your CD4 count, including:
A CD4-CD8 ratio. CD8 cells are another type of white blood cell in the immune system. CD8 cells kill cancer cells and other invaders. This test compares the numbers of the two cells to get a better idea of immune system function.
HIV viral load, a test that measures the amount of HIV in your blood.
