Viral load is a measurement of how much HIV is present in your blood. A sample of blood is drawn and sent to a lab for testing. Results are expressed as the number of copies of the virus per millilitre of blood. Each virus is called a "copy" because HIV reproduces by making copies of itself (replicating).
The viral load test gives a more accurate picture than a CD4+ cell count of what the virus is doing in your body at the moment. (The CD4+ test measures the effect HIV is having on your immune system.) The viral load test is used to help decide when to change antiretroviral medicines.
ByHealthwise Staff Primary Medical ReviewerE. Gregory Thompson, MD - Internal Medicine Brian O'Brien, MD, FRCPC - Internal Medicine Adam Husney, MD - Family Medicine Peter Shalit, MD, PhD - Internal Medicine, Infectious Disease