Once patients have been given an HIV diagnosis, they are advised to talk to an HIV specialist and undergo assessment of their current state of health in general and the condition of their immune system in particular. Two measurements are especially significant in this assessment – the CD4 count and the viral load.

• CD4 count: HIV reproduces particularly in CD4 immune cells (also known as T helper cells). In this process the virus destroys the cell so that the number of CD4 cells decreases as the HIV infection progresses and the immune system is thereby weakened. The count involves measuring the number of CD4 cells present.
• Viral load: The viral load indicates the number of viruses per millilitre of blood.

How the course of therapy will determine the frequency of visits to the doctor. As a rule, the most important checks (CD4 count and viral load) are done about every three months. Further investigations relate to possible HIV resistance, miscellaneous diseases, liver and kidney function as well as the cardiovascular system.