An elevated PSA is a signal — not a diagnosis. It means further investigation is needed, not that you have cancer. The majority of men with a raised PSA do not have prostate cancer.
You received a blood test result. The PSA is elevated. Your GP has referred you to a urologist, or perhaps you have been asked to repeat the test in six weeks. In the meantime, you are searching online at 11pm and finding a great deal of frightening information.
Let me give you a clear, honest explanation of what PSA is, what an elevated result actually means, and what the investigation process looks like. This is one of the most common situations I encounter in my clinic, and most of the anxiety around it comes from misunderstanding what PSA measures.
1. What PSA actually measures
PSA stands for Prostate-Specific Antigen — a protein produced by the prostate gland and secreted into the semen. Small amounts leak into the bloodstream in all men who have a prostate, and this is what the blood test measures.
The word "specific" refers to the fact that PSA is specific to the prostate — not to cancer. PSA is produced by normal prostate tissue, benign prostate enlargement (BPH), prostatitis (prostate inflammation), and prostate cancer alike. It is a marker of prostate activity, not a marker of cancer specifically.
PSA is prostate-specific — it is not cancer-specific. Elevated PSA means something is happening in the prostate. The most common cause is benign prostate enlargement (BPH), not cancer.
2. What an elevated result means
When a PSA result comes back above the reference range, it means that more PSA than expected is entering the bloodstream from the prostate. This can happen for several reasons — cancer is only one of them.
Elevated PSA means I have prostate cancer and need immediate surgery.
Approximately 75% of men with an elevated PSA do NOT have prostate cancer. A raised PSA triggers investigation — not a diagnosis or immediate treatment.
On a population level, about 25–30% of men with elevated PSA will be found to have prostate cancer on biopsy. Of those, a significant proportion will have low-risk, slow-growing disease that may never require active treatment. A smaller proportion will have clinically significant disease that benefits from treatment. The investigation process is designed to distinguish between these groups.
3. Understanding PSA values and ranges
PSA is measured in nanograms per millilitre (ng/mL). There is no universally "normal" level — PSA rises naturally with age as the prostate enlarges, and what is acceptable depends on a man's age and prostate size.
More important than any single reading is the PSA trend over time. A PSA that rises rapidly (more than 0.75–1 ng/mL per year) is more concerning than a stable PSA at a slightly elevated level. This is called PSA velocity.
PSA density — adjusting for prostate size
A man with a very large prostate naturally produces more PSA. PSA density divides the PSA value by the prostate volume (measured on ultrasound). A PSA density above 0.15 ng/mL/cc is considered more suspicious for cancer than if a large gland explains the elevated PSA entirely.
4. Other causes of elevated PSA
Before acting on an elevated PSA, it is essential to check for reversible causes that may have temporarily raised the level:
Prostatitis
Inflammation or infection of the prostate is one of the most common causes of an acutely elevated PSA. A recent urinary tract infection or prostate infection can raise PSA significantly — sometimes to 20–30 ng/mL. PSA should be rechecked after treating the infection.
Benign Prostatic Hyperplasia (BPH)
Benign prostate enlargement raises PSA in proportion to prostate volume. This is the most common reason for a mildly elevated PSA in men over 50 and should be assessed before biopsy.
Recent Procedures
A urinary catheter, cystoscopy (bladder camera), TRUS biopsy, or even vigorous rectal examination within the previous 24–48 hours can transiently elevate PSA. Ejaculation within 48 hours can also raise it slightly. Always disclose recent procedures when your PSA is tested.
Urinary Retention
Acute urinary retention — inability to pass urine — causes a spike in PSA. The PSA should return toward baseline after the retention is relieved.
A single elevated reading in the wrong context — after a procedure, during infection, or with urinary symptoms — should not automatically trigger a biopsy. A repeat PSA in 4–6 weeks after excluding reversible causes is appropriate in most cases.
5. What happens next — the investigation pathway
If a repeat PSA remains elevated and reversible causes have been excluded, the next step is not immediately a biopsy. The modern investigation pathway is more refined than it used to be:
Urology referral and clinical assessment
A urologist will assess your PSA in context — your age, prostate size on examination, PSA density, velocity, family history, and any urinary symptoms.
Multiparametric MRI (mpMRI)
Before any biopsy, an mpMRI of the prostate provides detailed imaging that identifies suspicious areas and significantly improves biopsy targeting. It also helps avoid biopsy in men whose MRI shows no suspicious lesion.
MRI-targeted biopsy (if indicated)
If the MRI shows a suspicious area (PIRADS 3 or above), a targeted biopsy of that specific zone is recommended — either cognitive fusion or software-assisted MRI/ultrasound fusion biopsy.
Histopathology results
Biopsy specimens are analysed by a pathologist who reports Gleason grade and the extent of cancer. This determines whether and what treatment is appropriate.
6. The role of mpMRI before biopsy
Multiparametric MRI is now the standard investigation before any biopsy decision for elevated PSA. It uses multiple MRI sequences — T2-weighted, diffusion-weighted, and dynamic contrast-enhanced imaging — to characterise the prostate tissue in detail.
Before mpMRI became standard, prostate biopsies were done "blindly" — systematic needle samples from all zones of the prostate, missing anterior tumours and including unnecessary samples from benign areas. MRI-targeted biopsy detects more clinically significant cancers and fewer insignificant ones.
The MRI is reported using the PIRADS (Prostate Imaging Reporting and Data System) score from 1 to 5:
- PIRADS 1–2: Very low/low likelihood of clinically significant cancer. Biopsy may be deferred with monitoring.
- PIRADS 3: Intermediate — uncertain. Clinical context and PSA density determine next steps.
- PIRADS 4–5: High/very high likelihood of clinically significant cancer. Biopsy is recommended.
A normal or low-suspicion mpMRI provides genuine reassurance and may allow monitoring rather than immediate biopsy. It is a powerful tool for avoiding unnecessary biopsies while catching clinically significant disease.
- What is my PSA density — and does my prostate size explain the elevated reading?
- Is there a reversible cause — infection, recent procedure — that we should exclude first?
- Should I have an mpMRI before any biopsy decision?
- What is my PSA trend — how does this reading compare to previous results?
- Do I have a family history risk — and does that change your recommendation?
- If the biopsy is recommended, what type — TRUS or transperineal? MRI-targeted or systematic?
This article provides general educational information about PSA testing and does not constitute personalised medical advice. PSA interpretation requires individual clinical assessment by a qualified urologist. Management decisions should be made in consultation with your treating doctor.