git add

Skip to main content

PSA test

Prostate specific antigen

Peer reviewed by Dr Toni Hazell, MRCGPLast updated by Dr Philippa Vincent, MRCGPLast updated 15 Dec 2024

Meets Patient’s editorial guidelines

In this series:Prostate problemsEnlarged prostateUrinary retentionUrethral strictureChronic prostatitisLower urinary tract symptoms in men

The PSA test (prostate specific antigen) is a blood test which assesses for the likelihood of prostate cancer. It is also used to monitor the treatment for prostate cancer.

The PSA blood level can also be increased in other conditions. Having an increased PSA test result does not therefore mean that prostate cancer is the diagnosis. At the moment there is no national screening programme for prostate cancer in the UK but there are currently studies looking at whether screening would be appropriate for prostate cancer.

The TRANSFORM randomised controlled trial is being planned to start during 2024. This will include a PSA test amongst others in assessing whether a prostate cancer screening programme is possible or appropriate.

At a glance

  • The PSA test measures prostate specific antigen in the blood.

  • Prostate specific antigen is a protein made by the prostate gland.

  • Several factors can cause a raised PSA level, including non-cancerous conditions.

  • A raised PSA level does not automatically mean you have prostate cancer.

  • The test may be offered to men aged 50 and over in England who request it.

  • Before the test, avoid ejaculating or heavy exercise for 48 hours.

This summary has been automatically generated from the article content to help readers quickly understand the key points.

In this article:

Video picks for Blood tests

Cross-section diagram of the prostate and nearby organs

Cross-section diagram of the prostate and nearby organs

Continue reading below

What is a PSA test?

The PSA test (prostate specific antigen) is a blood test that measures the level of prostate specific antigen in the blood. PSA is a protein which is made by the prostate gland. The PSA level in the bloodstream is measured in nanograms per millilitre (ng/mL). PSA is made by normal prostate cells but also by prostate cancer cells.

PSA test preparation

Back to contents

Before having a PSA test, it is important not to have:

  • An active urine infection.

  • Produced semen during sex or masturbation (ejaculated) in the previous 48 hours.

  • Exercised heavily in the previous 48 hours.

  • Had a prostate biopsy in the previous six weeks.

  • Had an examination of the back passage with a gloved finger (a digital rectal examination) in the previous week.

  • Had receptive anal intercourse for a period of 48 hours before a PSA test.

Each of these may produce an unnaturally high PSA result, resulting in unnecessary further investigations.

In England, the PSA test may be offered to any man aged 50 and over who requests it as long as they have considered the pros and cons of having the test. The test may be offered to younger men who have a higher risk of prostate cancer.

Continue reading below

The normal range for a PSA test​

Back to contents

The normal range changes as men age.

PSA Cut-off Values


Age (years)


PSA Cut-off

40-49

2.5 micrograms/litre or higher

50-59

3.5 micrograms/litre or higher

60-69

4.5 micrograms/litre or higher

70-79

6.5 micrograms/litre or higher

There are no age-specific reference limits for men older than 80 years of age. Any referral will depend on local guidelines.

Generally, the higher the level of PSA, the more likely it is to be a sign of cancer.

Benefits and limitations of a PSA test

Back to contents

Benefits of PSA testing

  • PSA testing may lead to prostate cancer being detected earlier, before symptoms develop.

  • Detecting prostate cancer early before symptoms develop may improve the outcome (prognosis) and improve the chance of a complete cure.

Limitations and risks of PSA testing

  • False negative result: about 15 out of 100 men with a negative PSA test may have prostate cancer.

  • False positive result: about 75 out of 100 men with a positive PSA test have normal prostate investigations, ie no evidence of cancer.

  • A false positive PSA test may lead to unnecessary investigations, such as a prostate biopsy, and there may be side-effects from this investigation, such as bleeding or infection. This is less common nowadays as MRI scans are a more common initial investigation which carry lower risks.

  • A positive result may also lead to unnecessary treatment. Many prostate cancers are slow growing and may not become evident during a man's lifetime. Side-effects of treatment are common and can be serious, such as urinary incontinence and sexual problems.

  • Current statistics suggest that, in men between the ages of 50 and 66 who are screened for 13 years, annual PSA testing would result in the avoidance of death from prostate cancer of 1.3 per 1000 men.

Continue reading below

Causes of a raised PSA level

Back to contents

A raised PSA level may be due to a diagnosis prostate cancer but about three out of four men with a raised PSA level will not be found to have prostate cancer.

Other conditions may also cause a raised PSA level, including:

PSA test results​

Back to contents

If the PSA level is not raised

Prostate cancer is less likely. A digital rectal examination may also be needed to rule this out.

If the PSA level is slightly raised

Prostate cancer is less likely. A digital rectal examination may also be needed to rule this out. Annual PSA tests might be advised.

If the PSA level is definitely raised

The GP will do an urgent referral to a urologist (a specialist doctor) for further tests for prostate cancer. The specialist will discuss the options for further investigations, which may include a sample taken (a biopsy) of the prostate gland and an MRI scan.

If prostate cancer is found, what are my options?

Back to contents

For information about the treatment options for prostate cancer, see the separate leaflet called Prostate cancer.

Patient picks for Blood tests

Blood tests

Tests and investigations

Blood tests

The main reasons to know your blood group are if you need to have a blood transfusion or if you are pregnant. You cannot request a blood test just to know your blood group on the NHS.

by Dr Hayley Willacy, FRCGP

Osmolality, osmolarity and fluid homeostasis

Tests and investigations

Osmolality, osmolarity and fluid homeostasis

Osmolality is a measure of the number of particles in a kg of the liquid they are dissolved in. Osmolarity is a measure of the number of particles in a litre of the liquid they are dissolved in. Fluid homeostasis is the term for keeping the concentration of the fluids in the body from changing. It is sometimes also referred to as fluid balance.

by Dr Hayley Willacy, FRCGP

Frequently asked questions

What specifically is a 'normal' PSA level, and does it vary for everyone?

A 'normal' PSA level changes as men get older. For example, a PSA cut-off of 2.5 micrograms/litre or higher is considered for men aged 40-49, while for men aged 60-69, it's 4.5 micrograms/litre or higher. There aren't specific normal ranges for men over 80, and referrals are based on local guidelines. Generally, a higher PSA level increases the likelihood of cancer.

If my PSA test is normal or only slightly raised, do I need to do anything else?

If your PSA level is not raised or only slightly raised, prostate cancer is considered less likely. In these cases, your doctor may also perform a digital rectal examination to help rule out prostate cancer. If it's slightly raised, annual PSA tests might be recommended.

Are there any factors I should be aware of that can temporarily increase my PSA level, even if I don't have prostate cancer?

Yes, several factors can temporarily raise your PSA level. These include having an active urine infection, ejaculating (during sex or masturbation) within 48 hours before the test, heavy exercise in the previous 48 hours, a recent prostate biopsy (within six weeks), a digital rectal examination in the past week, or receptive anal intercourse within 48 hours. Other conditions like acute retention of urine, a benign enlarged prostate, older age, acute prostatitis, a TURP operation, or having a catheter can also cause a raised PSA.

What happens if my PSA level is definitely raised?

If your PSA level is definitely raised, your GP will arrange an urgent referral to a urologist, who is a specialist doctor. They will then discuss options for further investigations, which might include an MRI scan and taking a biopsy (sample) of your prostate gland to check for cancer.

Could a raised PSA level mean I have something other than prostate cancer?

Yes, a raised PSA level doesn't automatically mean you have prostate cancer. In fact, about three out of four men with a raised PSA level are not found to have prostate cancer. Other common causes include a non-cancerous enlargement of the prostate, a urine infection, acute prostatitis, or conditions like the inability to pass urine causing an enlarged bladder.

What are the potential downsides of getting a PSA test?

There are several limitations to PSA testing. You could get a 'false negative' result, meaning you have cancer but the test doesn't show it (about 15 out of 100 men). You could also get a 'false positive' result, where the test suggests cancer, but further tests show no cancer (about 75 out of 100 men). A false positive can lead to unnecessary investigations like a biopsy, which carry risks such as bleeding or infection. Additionally, some prostate cancers grow very slowly and may not cause problems in a man's lifetime, but a positive result could lead to unnecessary treatment with potential side-effects like incontinence or sexual issues.

These questions and answers have been generated from the information in this article.

Further reading and references

Continue reading below

About the authorView full bio

Author image

Dr Philippa Vincent, MRCGP

General Practitioner, Medical Author

MB BS, Bsc, MRCGP (2000), DCH, DFSRH, DRCOG

Dr Philippa Vincent is an NHS GP working in North London.

About the reviewerView full bio

Author image

Dr Toni Hazell, MRCGP

MBBS, BSc, MRCGP, DFSRH, Dip GU med, DRCOG, DCH (London, UK, 2000)

Dr. Toni Hazell qualified from St. Mary’s Hospital Medical School and did her VTS at Northwick Park Hospital.

Article history

The information on this page is written and peer reviewed by qualified clinicians.

flu eligibility checker

Ask, share, connect.

Browse discussions, ask questions, and share experiences across hundreds of health topics.

symptom checker

Feeling unwell?

Assess your symptoms online for free

Sign up to the Patient newsletter

Your weekly dose of clear, trustworthy health advice - written to help you feel informed, confident and in control.

Please enter a valid email address

By subscribing you accept our Privacy Policy. You can unsubscribe at any time. We never sell your data.