PSA
A prostate protein raised by cancer — and by several entirely harmless things as well.
What it means
A protein produced by the prostate gland. Prostate cancer raises it — but so do a good many other things.
What else raises PSA:
- Simply getting older, since the prostate enlarges with age
- Benign prostate enlargement, which is extremely common
- A urine infection or prostatitis — which can raise it substantially for weeks
- Ejaculation in the previous 48 hours
- Cycling, or vigorous exercise
- A recent rectal examination or catheter
Most men with a raised PSA do not have cancer, and some men with prostate cancer have a normal one.
In practice
On male health screens, and available free from an NHS GP after a discussion for any man over 50.
There is no national prostate screening programme in the UK, precisely because the balance of benefit and harm is close.
Why it matters
Prepare properly before the test — no ejaculation, cycling or vigorous exercise for 48 hours, and not within six weeks of a urine infection. A great deal of unnecessary alarm comes from ignoring this.
A raised result is usually repeated before anything else happens, often after treating any infection.
Have the conversation before the test, not after it. The decision about whether to test at all is the difficult part — overdiagnosis is the central problem — and family history and Black African or Caribbean heritage both shift the argument towards testing.
Clinically reviewed by Dr Mohammad Zubair Khan, GMC 7563469
Last reviewed
August 30, 2026