Skip to content

    HIV & AIDS Health Center

    Font Size

    HIV (Human Immunodeficiency Virus) Infection - Exams and Tests

    Ongoing tests

    When you have HIV, two tests are done regularly to see how much of the virus is in your blood (viral load) and how the virus is affecting your immune system:

    • CD4+ cell counts provide information about the health of your immune system.
    • Viral load measures the amount of HIV in your blood.

    The results of these tests may help you make decisions about starting treatment or switching to new medicines if the ones you are taking aren't helping.

    Testing for drug resistance

    HIV often changes or mutates in the body. Sometimes these changes make the virus resistant to certain medicines. Then the medicine no longer works.

    Medical experts recommend testing the blood of everyone diagnosed with HIV to look for this drug resistance.1 This information helps your doctor know what medicines to use.

    You also may be tested for drug resistance when:

    • You are ready to begin treatment.
    • You've been having treatment and your viral load numbers stop going down.
    • You've been having treatment and your viral load numbers become detectable after not being detectable.

    How is AIDS diagnosed?

    AIDS is the last and most severe stage of HIV infection. It is diagnosed if the results of your test show that you have:

    WebMD Medical Reference from Healthwise

    Last Updated: August 12, 2014
    This information is not intended to replace the advice of a doctor. Healthwise disclaims any liability for the decisions you make based on this information.
    1 | 2 | 3
    1 | 2 | 3
    Next Article:

    Today on WebMD

    How much do you know?
    contemplative man
    What to do now.
    Should you be tested?
    HIV under microscope
    What does it mean?
    HIV AIDS Screening
    man opening condom wrapper
    HIV AIDS Treatment
    Discrimination Stigma
    Treatment Side Effects
    grilled chicken and vegetables
    obese man standing on scale
    cold sore