Viral load

Viral load is the amount of HIV in the blood, usually measured as copies of the virus per milliliter. It is one of the most important markers of how the infection and its treatment are going: the higher the number, the more active the virus; the lower it’s pushed, the better treatment is working and the more room the immune system has to recover.

When consistent treatment drives viral load below what lab equipment can measure, it is called undetectable. That carries two meanings: treatment is succeeding and the body is stable; and, when undetectable is sustained, the virus is not passed on through sex — the heart of U=U. Regular viral-load testing is a routine part of how people living with HIV manage their health.

Register note: viral load is a neutral clinical measure. “Undetectable” is good news, and people in the community often share it as an all-is-well update — it means “well controlled,” not “the virus is gone.”

Common misreading: reading “undetectable” as “cured, safe to stop meds.” The virus is suppressed, not cleared, and rebounds if treatment stops — which is why serodiscordant partners need to understand that U=U depends on staying undetectable.