Prostate cancer screening is the one area of urology where a confident, simple answer should make you suspicious. It involves a genuine trade-off, and any doctor who tells you the test is straightforwardly good or straightforwardly useless is skipping the part you need to understand.
This article lays out both sides so you can make the decision yourself.
What PSA actually measures
Prostate-specific antigen is a protein made by the prostate. A small amount leaks into the bloodstream normally. Anything that irritates, enlarges or disrupts the gland leaks more.
Note what that sentence does not say. PSA is specific to the prostate, not to prostate cancer. That single distinction explains almost everything confusing about the test.
Why a raised PSA usually isn't cancer
Most men with a raised PSA do not have prostate cancer. Common innocent causes:
- Benign prostatic enlargement — more prostate tissue simply makes more PSA. See our article on enlarged prostate
- Urinary infection or prostatitis — can push PSA dramatically high, and it falls again after treatment
- Recent ejaculation — within about 48 hours
- Cycling or prolonged pressure on the perineum
- Recent catheterisation, cystoscopy or a prostate examination
- Simply getting older
So a raised PSA is a reason to look further — not a diagnosis, and not a reason to panic while you wait for the next appointment.
The reverse also holds: a normal PSA does not fully exclude cancer. Some significant cancers produce relatively little PSA. This is why the blood test is interpreted alongside a physical examination rather than in isolation.
There is no single "normal" PSA
Patients often arrive having compared their number to a threshold found online. Those thresholds are cruder than they look. PSA rises naturally with age and with gland size, so the same figure carries different weight in a 45-year-old with a small prostate than in a 72-year-old with a large one.
What a urologist actually looks at:
- The trend. Two or three readings over time say far more than one. A number climbing steadily matters more than a stable one that happens to be above a cut-off.
- PSA density — the level relative to prostate volume measured on ultrasound or MRI.
- Free-to-total PSA ratio, in some cases.
- The digital rectal examination. A hard or irregular gland changes the picture regardless of the number.
These drugs, used for prostate enlargement and sometimes hair loss, roughly halve PSA levels. If the doctor interpreting your result doesn't know you take one, a genuinely concerning reading can be waved through as normal. Always mention it.
The honest trade-off
The case for testing: prostate cancer is common, and early disease is curable while advanced disease is not. Screening finds cancers years before they cause symptoms — by which point they are often incurable.
The case against: many prostate cancers grow so slowly they would never have caused harm in a man's lifetime. Finding and treating those cancers offers no benefit but real cost — surgery and radiotherapy carry risks to urinary control and erectile function. This is called overdiagnosis, and it is the genuine problem with screening, not a talking point.
The good news is that the trade-off has shifted meaningfully in favour of testing over the last decade, for two reasons:
MRI before biopsy. Rather than biopsying everyone with a raised PSA, an MRI is done first. If it looks reassuring, many men avoid a biopsy entirely. If a suspicious area shows, the biopsy targets it. This detects more of the aggressive cancers that matter while finding fewer of the trivial ones — the exact thing overdiagnosis critics were right to complain about.
Active surveillance. Low-risk cancer no longer means automatic treatment. Many men are monitored with regular PSA, MRI and occasional biopsy, and treated only if it shows signs of progressing. Diagnosis and treatment have been decoupled.
Who should consider testing
Screening is a shared decision, not an automatic test. Broadly:
- Average-risk men: a conversation from around age 50.
- Higher-risk men: start earlier, around 40 to 45. That means a father or brother with prostate cancer, a strong family history of breast or ovarian cancer, or a known BRCA mutation.
- Men aged roughly 55 to 69 get the clearest benefit; testing every two to four years is reasonable for average risk.
- Older men or those with limited life expectancy: benefit falls away, because slow-growing disease will not have time to cause harm. Screening a frail 80-year-old is more likely to cause problems than solve them.
Separately from screening: symptoms are not screening. If you have blood in your urine, bone pain, unexplained weight loss or new difficulty passing urine, that is not a screening conversation — get assessed.
What happens after a raised result
- Repeat it. Often the second reading is normal, particularly if the first followed infection, cycling or ejaculation.
- Treat infection if present, and retest afterwards.
- Examination and ultrasound to assess gland size and calculate PSA density.
- MRI if concern persists. A reassuring scan may mean no biopsy at all.
- Targeted biopsy only if the MRI shows something worth sampling.
Note how far down the list biopsy sits. Going straight from one raised PSA to a biopsy is not current best practice.
Frequently asked questions
Does a high PSA mean I have prostate cancer?
No. Most men with a raised PSA do not have cancer. Benign enlargement, infection, recent catheterisation, cycling and ejaculation all raise it. It is a reason to look further, not a diagnosis.
What is a normal PSA level?
There isn't one. PSA rises with age and gland size, so the same figure means different things in different men. The trend across readings is more informative than any single value.
Do I need a biopsy if my PSA is raised?
Not immediately. Current practice is to repeat the test and use MRI to decide whether a biopsy is needed and where to target it. This avoids many unnecessary biopsies.
Is the PSA test painful?
It's an ordinary blood test. The digital rectal examination that accompanies it takes a few seconds and is uncomfortable rather than painful.
Should I avoid anything before the test?
Avoid ejaculation and vigorous cycling for 48 hours beforehand, and postpone the test if you have a urinary infection.
Medically reviewed by Dr. Navdeep Garg, MCh (Urology), FEBU. This article is general information about urological conditions and does not constitute medical advice. Treatment decisions depend on individual assessment. For any medical concern, please consult a qualified physician.