advertisement

cd4+ count test

test overview

a cd4+ count is a blood test to see how well the immune system is working in people who have been diagnosed with hiv. cd4+ cells are a type of white blood cell. white blood cells are important in fighting infections. cd4+ cells are also called t-lymphocytes, t-cells, or t-helper cells.

hiv infects cd4+ cells. the number of cd4+ cells helps determine whether other infections (opportunistic infections) may occur. if hiv isn't treated, cd4+ counts generally go down as hiv gets worse. in most cases, a low cd4+ count means you have a weakened immune system and a higher chance of getting opportunistic infections.

why it is done

cd4+ counts are done to:

  • keep track of how the hiv infection is affecting your immune system.
  • help diagnose aids. if you don't get treatment, hiv infection can progress to aids.
  • check to see if you're at risk for other infections (opportunistic infections).
  • decide whether to start treatment to prevent opportunistic infections, such as medicines to prevent pneumocystis pneumonia.

how often your cd4+ count is checked depends on your treatment, your health, and your prior cd4+ count results.

how to prepare

in general, there's nothing you have to do before this test unless your doctor tells you to.

how it is done

a health professional uses a needle to take a blood sample, usually from the arm.

watch

how it feels

when a blood sample is taken, you may feel nothing at all from the needle. or you might feel a quick sting or pinch.

risks

there is very little chance of having a problem from this test. when a blood sample is taken, a small bruise may form at the site.

results

in people who have hiv, the cd4+ count almost always goes up with treatment. low cd4+ counts make infections more likely.

credits

current as of: may 13, 2023

author: healthwise staff
clinical review board
all healthwise education is reviewed by a team that includes physicians, nurses, advanced practitioners, registered dieticians, and other healthcare professionals.

this information does not replace the advice of a doctor. healthwise, incorporated, disclaims any warranty or liability for your use of this information. your use of this information means that you agree to the terms of use. learn how we develop our content.

advertisement

advertisement