Think of HIV as a car speeding towards an accident, which is the point at which you become ill. The viral load tells you how fast the car is speeding and the CD4 count shows how many miles of road are left before the accident.

Continuous monitoring of viral load levels along with other indicators help you to decide whether to start anti-HIV treatment. If the treatment is successful, your viral load levels will fall. The goal of anti-HIV therapy is to reduce viral load levels so that they are undetectable. Even if your viral load does become undetectable, this does not mean that the Virus has been eradicated from your body, but that its level has been greatly reduced and disease progression slowed down or stopped.

Your blood should be tested regularly (about every 3-6 months) to check both CD4 cells and viral load. If there are any sudden changes, unexpected results or 'blips' a second test should be taken much sooner. If you start or change anti-HIV therapy you should get an extra test within a month to see how it is working. The results of your tests should normally be available within 2 - 3 weeks.