What causes a raised PSA? Causes, meaning and what happens next
Prostate and Bowel Cancer Tests · 6 min read
A raised PSA result is unsettling, and the first thing worth knowing is this: most men with a raised PSA do not have prostate cancer.
PSA — prostate specific antigen — is a protein made by the prostate. Some leaks into the blood normally. Several things increase how much, and cancer is only one of them.
What causes a raised PSA?
- Benign prostatic hyperplasia (BPH) — non-cancerous enlargement, extremely common with age and probably the most frequent cause of a raised reading
- Prostatitis — inflammation or infection of the prostate
- Urinary tract infection
- Recent vigorous exercise, particularly cycling in the 48 hours before testing
- Recent ejaculation, within about 48 hours
- Digital rectal examination shortly before the test
- Simply getting older — the normal range rises with age
What the numbers mean
The commonly used threshold is 4 ng/mL, which is what most rapid home tests are set to. Above that, further investigation is usually considered.
But the threshold is a convention, not a wall. Age-specific ranges are often used: a reading of 3.5 means something different at 45 than at 75. And roughly three in four men with a raised PSA turn out not to have cancer, while around one in seven men with a normal PSA do have it. PSA is a prompt to look further, not an answer.
Why a GP may use a different threshold from 4 ng/mL
Home rapid tests use a single cut-off of 4 ng/mL. NHS guidance instead uses age-specific ranges, because PSA normally rises with age. In practice that means a man in his 40s or 50s may be investigated at a lower PSA than 4 ng/mL, while a level above 4 can still be normal for an older man. So a result below 4 on a home test does not necessarily mean a GP would consider your PSA normal for your age, and a result above it does not necessarily mean something is wrong.
If you want your result judged against your own age band, ask your GP for a laboratory PSA test. Our PRIMA PSA test kit and PSA test packs are screening aids that can prompt that conversation.
What happens after a raised result
Your GP will typically repeat the test in a laboratory, since a rapid test indicates only whether you are above or below the threshold, not the actual number. They will ask about symptoms, examine the prostate, and consider your age and family history.
If further investigation is warranted, the current UK pathway usually involves an MRI scan before any biopsy. This is a significant improvement on older practice — it means many men avoid a biopsy entirely.
Before you test
To avoid a falsely raised reading, avoid vigorous exercise and cycling for 48 hours beforehand, avoid ejaculation for 48 hours, and do not test while you have a urinary infection.
If your result is normal
A normal PSA is reassuring but not conclusive. Some prostate cancers do not raise PSA at all. Report any urinary symptoms — difficulty starting, weak flow, getting up at night, blood in urine — to a GP regardless of a test result.
Who should consider testing
In the UK there is no routine PSA screening programme, because the evidence on whether population screening does more good than harm is genuinely mixed. Men over 50 can request a PSA test from their GP. Testing earlier, from around 45, is often suggested for men with a family history of prostate cancer, and for Black men, who have roughly double the lifetime risk.
This is a decision worth discussing with a GP rather than making on a test result alone.
Common questions
Does a raised PSA mean I have prostate cancer?
No, most men with a raised PSA do not have prostate cancer. Common non-cancerous causes include an enlarged prostate, prostatitis, a urinary infection, recent vigorous exercise or recent ejaculation.
What should I avoid before taking a PSA test?
To reduce the chance of a falsely raised reading, it's worth avoiding vigorous exercise or cycling, and ejaculation, for 48 hours beforehand, and not testing while you have a urinary infection.
What happens after a raised PSA result?
A GP will usually repeat the test in a laboratory, ask about urinary symptoms, and examine the prostate. In the current UK pathway, an MRI scan is typically done before any biopsy is considered.
Does a normal PSA result rule out prostate cancer?
Not completely. A normal PSA is reassuring but some prostate cancers don't raise PSA levels, so any urinary symptoms are worth reporting to a GP regardless of a test result.
Who is more likely to be advised to test earlier than 50?
Testing from around age 45 is often suggested for men with a family history of prostate cancer and for Black men, who have a higher lifetime risk. This is worth discussing with a GP rather than deciding alone.