Q and A


What do my viral load test results mean?

Please can you explain how viral load results mean?

I got my results back and I don’t understand them. It says log units is 2.777 and my RNA copies is 599 cp/mL.

Is this low or high? My CD4 count is 697.



Thanks for your question – and it is good that you want to understand your test results.

Sometimes this can be dfficult if your doctor has not explained them clearly. It is also okay to ask your doctor or nurse to explain anything that you are not sure of.

Viral loads tests tells you how much virus is in a millilitre of blood (or another body fluid being measured).

When not on treatment, viral load can range from undetectable to several millions. For anyone on HIV treatment (ART), viral load should ideally get to undetectable, This is defined as being less than 50 copies/mL.

Your test results are the 599 copies/mL, so your viral load is still detectable at 599.

The ‘2.777 log units’ from your test results is a slightly complicated way of saying exactly the same thing as ‘599 copies/mL’.

Because viral loads have such a huge range of numbers they are sometimes expressed in ‘log units’ to make it easier to write them on graphs and diagrams. Doctors and scientists use log scales to look at changes to viral loads over time. See this table of log units compared to viral loads in copies/mL.

Whether this is considered high or low depends on whether or not you are on treatment.

  • If you’re not on treatment yet this is a relatively low viral load, which is a good thing.
  • If you are on treatment, then if you only recently started ART, your viral load might still be going down.
  • If you have been on treatment for more than six month, please talk to your doctor about why the results in not undetectable.

For more information about viral loads and how they relate to both treatment and infectiousness you can also have a look at the following links:

Viral Load and Treatment
Viral Load and Infectiousness

If you tell me if you are currently on treatment or not I can provide more individual information, Also, if you are on treatment, when did you start?

This answer was updated in January 2016 from a question first posted on 5 April 2012.


  1. Amy

    I have been on treatment for 6 years I have been undetectable dor a few years. On my last pathology test it says my viral load is 20cpml. I take my tablet religiously. I may have on an odd day missed it but one very few occasions. My doc says we will monitor and it’s it’s not drastically bad. Can you explain what does 20 cpml mean and how concerned should I be. Will my viral load go down?

  2. Josh Peasegood

    Hi Amy, 20 copies is an excellent viral load. Your medication is still working very well and your viral load is being suppressed to what is considered undetectable levels. Any viral load below 200 is considered undetectable and U=U will still apply: https://i-base.info/u-equals-u/

    Your viral load is nothing to be concerned about. Your recent value may be because of a more sensitive test, a lab error, or even if you were ill when you had your test. It is possible that this was a normal blip in your viral load. Though testing below this is difficult to remain specific. If the test had a cut off of 20, it is possible that you have had a viral load of 19 in the past. The test could not measure this and read as undetectable instead. In this case you would have only gone up by 1.

  3. Josh Peasegood

    Hi Joe, without the ranges of the test you have taken I am unable to comment on this result.

    As for your viral load, as you have increased to 169 from undetectable, are you able to get a second test done? This would confirm if it was a lab error (which is likely) or if your viral load has increased to this point.

    A viral load of 169 is really good still. It means U=U still applies and in this context you are still considered undetectable: https://i-base.info/u-equals-u/

  4. Joe

    I don’t understand these readings on my test, on treatment, right now it’s 169 and below it hiv 1 pcr 2.23. And it’s flag as H, what does this mean, and was undetectable a year ago

  5. Lisa Thorley

    Hi Monica,

    Are you taking ARVs? If you are how long have you been on them for?

  6. Monica

    Hi my viral load is 149 is that bad or good

  7. Lisa Thorley

    Hi Yolanda,

    How long have you been on treatment for?
    Has your viral load been less than 573?

    When thinking about transmission the PARTNER study, please see here: https://i-base.info/qa-on-the-partner-study/ Involved people who had a viral load of less than 200 copies ml. Therefore, though the risk will be minimal, there’s still a risk because your viral load is detectable.

  8. Yolanda

    my viral load is 573 is possible that I may have infected my partner


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