Prostate specific antigen
Also written: PSA
What it measures
A substance produced by the prostate, measurable in blood.
Why it is ordered
⚠️ Rises in many non-cancer situations: inflammation, benign enlargement, after cycling, after intercourse, after a rectal examination. This is therefore a test to DISCUSS BEFORE doing, not one to add to a package on your own.
How to prepare
Avoid cycling and intercourse for a few days beforehand. Do not test right after a rectal examination or during a urinary infection.
Units
ng/mL — convert here
What to ask
- Given my age and situation, what are the benefits and harms of this test
- If it is raised, what chain of steps follows
- Does the trend over several tests matter more than one value
This page does not include reference ranges and does not say whether your number is high or low. Reference ranges differ between laboratories and between people — read yours on your own report, with your clinician.