Your viral load is important because it tells your doctor how much HIV is in your blood. Your viral load is measured by a blood test. You viral load will be checked when you learn that you are HIV positive. Your doctor may want to check your viral load regurly, usually along with your CD₄ cells. The results of the test are important in deciding when to start treatment and, once treatment has started, how well your medicines are working.

In some cases, your viral load will be reported as "undetectable." This is good because the lower the viral load in your blood the better. An undetectable viral load means that your HIV medicines are doing a good job to help your body fight HIV.

An undetectable viral load level does not mean that you no longer have HIV. You are still infected abd can pass the virus
to others.