Viral load - meaning and definition
AlsoHIV viral loadviral load testviral load count
Not yet reviewed by a clinician. This health entry was written from the public-health sources listed below and is general information only. It is not medical advice.
Definition
Viral load is the amount of a virus, such as HIV, in a sample of blood; for people on HIV treatment, a low or undetectable viral load is the main sign treatment is working.
At a glance
- Viral load is measured in copies of the virus per millilitre of blood.
- People living with HIV have it checked regularly, especially after starting or changing treatment.
- A low or undetectable viral load is the main sign HIV treatment is working.
- Undetectable means below the level standard tests can measure.
- An undetectable viral load means HIV cannot be passed on through sex.
In detail
Viral load is measured in copies of the virus per millilitre of blood. People living with HIV have it checked regularly, especially after starting or changing treatment.
When treatment brings the viral load below the level standard tests can measure, it is called undetectable. Keeping it undetectable protects the person's health and means HIV cannot be passed on through sex.
In a sentence
- My viral load has been undetectable since my second check-up.
- The HIV nurse explained what the viral load result on the report meant.
Not to be confused with
- CD4 count
A CD4 count measures immune cells, while viral load measures the virus itself.
Common questions
What does undetectable viral load mean?
It means HIV treatment has lowered the amount of virus in the blood below what standard tests can measure. It protects the person's health and means HIV cannot be passed on through sex.
How often is viral load checked?
It is checked regularly, more often after starting or changing treatment. The exact schedule depends on local guidelines and the person's health, so the HIV clinic will advise.