The PSA Test: Who Should Consider One and What Can Affect the Result?

A PSA test may be worth discussing if you have possible prostate symptoms, a higher inherited or family risk, a previous result that needs follow-up, or you want to make an informed decision about early detection.

It is not a simple yes-or-no cancer test. PSA can be raised for non-cancerous reasons, can be normal in a man with cancer, and may lead to further investigations for a cancer that would never have caused harm.

What does the PSA test measure?

PSA stands for prostate-specific antigen. It is produced by prostate cells and measured in a blood sample. The result is reported in nanograms per millilitre, or ng/mL.

A higher value can occur with:

• prostate cancer;
• benign prostate enlargement;
• urine or prostate infection;
• inflammation;
• recent ejaculation or prostate stimulation;
• vigorous exercise or cycling;
• urinary retention or a catheter; and
• a recent prostate procedure.

Age and the amount of benign prostate tissue also affect the result. The result must therefore be interpreted in context.

Who may want to discuss testing?

Men with possible symptoms

Urinary symptoms usually have a benign cause, but persistent difficulty urinating, visible blood, unexplained weight loss, new persistent bone pain or an abnormal clinical finding can justify investigation. Symptoms do not replace the need for proper assessment, and some require urgent referral rather than routine screening.

Men with a family history

Risk is higher if a father or brother had prostate cancer, particularly at a younger age or when more than one close relative was affected. A family pattern of breast, ovarian, pancreatic or prostate cancer may also suggest an inherited risk and can influence the discussion.

Black men

Black men have a higher risk of prostate cancer and are more likely to be diagnosed at a younger age. This does not make testing compulsory, but it is relevant to an informed decision about when to discuss PSA.

Men with an inherited genetic variant

A pathogenic BRCA2 variant is associated with higher prostate-cancer risk. In March 2026, the UK National Screening Committee recommended a targeted screening programme using PSA every two years for men aged 45 to 61 who have a pathogenic BRCA2 variant and a relevant family history of breast, ovarian, pancreatic or prostate cancer.

This is a narrowly defined national screening recommendation. Local implementation and individual clinical testing should be discussed with the appropriate NHS genetics, GP or specialist service.

Men without symptoms

There is no UK population-wide PSA screening programme. A man without symptoms can still ask for an informed discussion about the potential benefits and harms. Age, life expectancy, personal risk and what he would want to do with an abnormal result all matter.

What are the possible benefits?

PSA testing may:

• find a clinically important cancer before symptoms develop;
• enable monitoring or treatment at an earlier stage; and
• provide a useful baseline or trend in selected men.

What are the possible limitations and harms?

PSA testing may:

• be raised when there is no cancer, causing worry and further tests;
• be below a referral threshold despite cancer;
• identify a slow-growing cancer that would never have affected lifespan or quality of life;
• lead to MRI or biopsy, with their own inconvenience and risks; and
• lead to treatment that may affect erections, continence, bowel function or wellbeing.

This balance is why consent should be informed rather than reduced to “it is only a blood test”.

How should I prepare?

For 48 hours before a PSA test, NHS advice is to avoid:

• ejaculation;
• anal sex;
• vigorous exercise; and
• cycling.

Wait four to six weeks after a urine infection has cleared. Tell the clinician about recent urinary retention, catheterisation, prostate examination or procedures, because the test may need to be delayed.

Some medicines can lower or otherwise affect PSA interpretation. Provide a complete medication and supplement list; do not stop anything without medical advice.

Is a digital rectal examination necessary?

Not solely to screen for prostate cancer. UK urological experts have highlighted that the rectal examination is a poor stand-alone cancer test and it is not required simply before referral for a raised PSA.

It can still be clinically useful when assessing urinary symptoms, pain or a suspected prostate abnormality. It should be offered only for a clear reason, with an explanation and consent.

What happens after the result?

If PSA is not raised

The result reduces some concern but does not guarantee there is no cancer. Persistent red-flag symptoms, a changing pattern or a significant inherited risk still need appropriate follow-up.

If PSA is raised

A raised result is not a cancer diagnosis. The clinician may check for infection and temporary influences, compare previous results and repeat the test. If the level or clinical picture meets the relevant threshold, referral to urology is considered.

Specialist assessment often uses multiparametric MRI before deciding whether biopsy is needed. The exact pathway depends on current NICE guidance and local services.

If PSA changes over time

A trend can be useful, but PSA velocity should not be interpreted in isolation. Laboratories, infections, benign enlargement and the interval between samples all matter.

Questions to ask before deciding

1. What is my personal risk based on age, ethnicity, family history and genetics?
2. Is anything likely to distort the result today?
3. What would happen if the result were raised?
4. Would I be willing to consider MRI, biopsy, monitoring or treatment?
5. When, if ever, should the test be repeated?