Medical Terms

CD4 (T-cells)

  • CD4 cells, sometimes called T-cells, are white blood cells which help fight infections.
  • A person who is not HIV positive may have a CD4 count anywhere between 500 and 1,200.
  • HIV can infect CD4 cells and use them to produce more HIV.
  • Most people with HIV find that their CD4 count usually declines over a number of years.
  • If your CD4 count drops below 350, or starts falling rapidly, your doctor should talk to you about whether you need to start anti-HIV medication.

Viral Load

  • A Viral Load is a description of the amount of HIV in your blood.
  • Viral load measurements can go up and down from one blood test to the next.
  • Your viral load should ideally only be tested when you are well. Having an infection or recent vaccination could cause your viral load to temporarily increase.
  • If your viral load results over a period have been consistently increasing, along with other indicators such as your CD4 count decreasing, starting treatment may begin in consultation with your doctor.