What it measures
Prostate-specific antigen (PSA) is a protein made by the prostate gland, and a small amount passes into the blood. Levels can rise with an enlarged prostate, a urine infection, inflammation or prostate cancer, so a raised result is not a diagnosis on its own.
Why people test it
- Checked when there are urinary symptoms, such as needing to pee more often or a weak flow.
- Asked for by men and anyone with a prostate who want a check; a raised result usually leads to further tests.
- Monitored over time in people with a known prostate condition.
- Measured before and during testosterone therapy as part of routine monitoring.
Typical range
Ranges vary between labs with the method used and with age, and your report shows the lab's own range. One NHS trust's lab uses age-related upper limits, from below 2.5 µg/L at 49 and under to below 6.5 µg/L at 70 and over. Source: Leeds Teaching Hospitals NHS Trust: Blood Sciences Reference Range Database v3.20.
Finger-prick or vein?
A finger-prick sample is usually fine for PSA.
Ejaculation, exercise that leaves you out of breath and cycling in the 48 hours before the sample can raise PSA, as can a urine infection.