Q and A


What are CD4 cells, CD4:CD8 ratio and CD4 percentage?


CD4 cells are a type of lymphocyte (white blood cell). They are an important part of the immune system. CD4 cells are sometimes called T-cells.

There are two main types of T-cells. T4 cells, also called CD4+, are “helper” cells. They lead the attack against infections. T8 cells, (CD8+), are “suppressor” cells that end the immune response. CD8+ cells can also be “killer” cells that kill cancer cells and cells infected with a virus.

The normal ranges for CD4 and CD8 counts varies depending on the lab and test, but for an HIV negative person a normal CD4 count is in the range 460 to 1600. This is an approximate. Anywhere in this ranges is fine.

Although generally a higher CD4 is good, nn HIV negative person with a normal CD4 count of 1200 is not more healthy than someone whose normal count is 600.

A normal CD8 range is from 150 to 1000.

The ratio of CD4 cells to CD8 cells is also often reported. This is a measure of how balanced your immune function is. The ratio is calculated by dividing the CD4 value by the CD8 value. In HIV negative people, the normal range for this ratio is between 0.9 and 1.9, meaning that there are about 1-2 CD4 cells for every CD8 cell.

In HIV positive people not on treatment, this ratio drops over time until there are more CD8 cells than CD4 cells (i.e. the ratio drops to less than 1.0).

Because the CD4 counts can vary from day to day and hour to hour, if you ever get an unexpectedly high or low CD4 count your CD4% (CD4 percentage) will indicate if this is a real change. The percentage refers to total lymphocytes.

If your test reports CD4% = 34%, that means that 34% of your lymphocytes were CD4 cells.

This percentage is more stable than the number of CD4 cells. The normal range for HIV-negative adults is about 40% (range 30% to 60%).

Information on this website is provided by treatment advocates and offered as a guide only. Decisions about your treatment should always be taken in consultation with your doctor.


  1. Hi Tamirat,
    These results mean that your immune system is doing very well. The most important of these is your CD4 count. This is the standard measure used to monitor somebody’s immune system when they have HIV. A ‘normal’ CD4 count (without HIV) is anything between 500-1600. While your CD4 count is above 350 it is very unlikely you will have any symptoms or HIV related illnesses. You can read more about CD4 counts here.

    There is nothing you can do- expect take ARVs- to improve your CD4 count. If you are not on treatment your CD4 count is likely to decrease over time until you decide to start treatment.

  2. my cd4 count is 812 & my cd8 count is 2023 cd4% is 25 woud you tell me my health status & how to improve my cd4/cd8 ?

  3. Hi Mukasa,

    A ratio is usually written as 1:9 or 1:2 and so on. A CD4% of 40 is good and is likely to mean your immune system is strong. The best way of measuring this though is usually the absolute CD4 count. Do you know what your CD4 count is?

  4. What is the problem if my cd4 and cd8 ratio is 40%?

  5. Hi Jack,

    Everybody progresses at different rates so you can’t tell from one CD4 count how long it will take for your CD4 count or ratio to drop. The best way to assess this is to study the CD4 count over time and see how it changes. This is a very high CD4 count though which means that your immune system is still strong. Please follow this link for more information about how CD4 counts progress in different people.

  6. in hiv how quick turns cd4/cd8 ratio less than 1? i have cd4 904/μlt and cd8 561/μlt ratio 1.61. thank you

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