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HIV Viral Load Test

Test Overview

A viral load test measures how much HIV is in the blood. It's first measured when you're diagnosed with HIV. This serves as the baseline. Future measurements are compared with it. With treatment, the viral load should go down. Within a few months, there should be very little virus in your blood.

Why It Is Done

A viral load test is done to watch for changes in an HIV infection. Your doctor uses it to see how well your treatment is working. This information helps guide your treatment options.

A goal of treatment is to reach an undetectable viral load. This means that the amount of the virus is too low for the test to detect. When the virus is undetectable, you cannot pass HIV to other people through sex.

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.


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.


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.


Each lab has a different range for what's normal. Your lab report should show the range that your lab uses for each test.

Viral load results are reported as the number of HIV copies in a millilitre (copies/mL) of blood. Each virus is called a "copy," because HIV reproduces by making copies of itself (replicating).

HIV viral load


HIV is not detected (undetectable) in the blood.


HIV is detected in the blood. Your doctor will compare your current measurement with previous values.

If the viral load drops, it means that the infection is being suppressed or controlled.

If you are not being treated, an undetectable viral load result doesn't mean that you no longer have HIV in your blood. It means that the amount of HIV in the blood was too low for the test to detect. HIV still can be passed to another person even when the viral load cannot be detected in people who are not on medication. U=U (undetectable = untransmittable) only when you are taking taking PEP (post-exposure prophylaxis) or PrEP (pre-exposure prophylaxis).


Adaptation Date: 3/20/2024

Adapted By: Alberta Health Services

Adaptation Reviewed By: Alberta Health Services

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