What is the CD4 count or T count?
The CD4 cell count is a very crude measure as to the strength of your immune system. The CD4 helper T-lymphocyte is the predominant immune cell that the HIV virus infects and destroys. Over time the body can not replace these lost CD4 cells and the size and function of this population declines and as it does so, the ability of your immune system to fight infection will also deteriorate. The lower the CD4 count the less able your immune system is to fight infection and the more serious and extensive the range of infections you become susceptible to. A normal CD4 count is approximately 800 cells. When the CD4 count falls below 200 cells you become increasingly susceptible to AIDS defining illnesses such as Pneumocystis pneumonia (PCP).
