What my CD4 count and viral load tell me

As part of your regular checkups, your doctor will recommend blood tests to monitor your health. Two of the most important tests check your CD4 count and your viral load.

What is a “CD4 count”?

Your CD4 count tells you how your immune system is doing. The higher the number, the better.

CD4 cells are the “bosses” of the immune system. They lead the fight against invading germs and viruses. Your CD4 count tells you how many CD4 cells you have in a cubic millimetre (mm3) of blood. A normal CD4 count is anywhere from 500 to 1,500.

A low CD4 count puts you at greater risk of getting sick. Once you start HIV treatment, your CD4 count will likely rise, and many people on HIV treatment have normal CD4 counts.

What is “viral load”?

Your viral load is the amount of HIV that is in your blood. The lower your viral load, the better.

If you are on HIV treatment and the treatment is working, your viral load will fall to a level too low for a test to detect (this is called an undetectable viral load). When you have an undetectable viral load, it does not mean that you’re cured or that the HIV is gone, but it does mean that your HIV is under control and that you cannot pass HIV to your sex partners.