Prostate Specific Antigen

The prostate produces a protein called prostate specific antigen (PSA). PSA helps to make your semen more liquid.

What is PSA?

The prostate produces a protein called prostate-specific antigen (PSA). PSA helps to make your semen more liquid. Some PSA leaks into your blood. How much will depend on:

  • Your age – it raises slightly as you get older and your prostate grows
  • The health of your prostate.

Important things to know

What is a PSA test?

A PSA test is a simple blood test. This measures the amount of PSA in your blood. The test only takes a few minutes and can be done at your GP surgery. 

What can a PSA test tell me?

  • It can help you to find out if you are more likely to have prostate cancer
  • Having a raised PSA does not necessarily mean you have prostate cancer.

If your PSA level is raised, you will need to have more tests at the hospital. This could include an MRI scan, biopsy of your prostate or both. 

When will I get my results?

  • The results of your PSA test may take one-to-two weeks.
  • The amount of PSA in your blood is measured in nanograms of PSA per millilitre of blood. You may see this written as ng/ml on your test results.
PSA blood test
Frequently asked questions (FAQs) about the PSA test

Who can have a PSA test?

You can ask for a free PSA test if you are a man or trans woman over 50 years old. This is part of the NHS informed choice programme. You are at higher risk of getting prostate cancer if:

  • You are of Black ethnic origin 
  • You have a family history of prostate cancer (e.g., father or brother).

If you are at higher risk, you can talk to your doctor about getting a PSA test from the age of 45. 

Black Father and son looking at an iPad


  • The South East London Cancer Alliance has teamed up with prostate cancer patients from Black African and Caribbean communities in south east London and students at the London College of Communications. They developed a series of thought-provoking animations to encourage conversations about prostate cancer. 
  • The series, was also developed in collaboration with Partnership Southwark. It aims to support Black communities to have open conversations about the risk of Black men developing prostate cancer and the importance of getting tested.
  • The animations are narrated by the patients who have shared their experience of being diagnosed with prostate cancer.

This video talks about the importance of being diagnosed early. 


© SEL Cancer Alliance [2023] All rights reserved. Information taken 13/06/23


The NHS recommends that Black men over the age of 45 speak to their GP about their risk of prostate cancer, even if people are not experiencing symptoms.

If you are having a PSA test as part of a general health check-up or screening, you will be asked to avoid the following for 48 hours before your PSA test:

  • Exercising heavily 
  • Sexual activity.
black man on bicycle

The PSA can be raised for many reasons: 

  • An infection of your pee (urinary tract infection or UTI): You may be advised to wait for six weeks after a UTI before having a PSA test. 
  • Stimulation or massaging of your prostate: This can include:
    • Heavy exercise – especially cycling 
    • Ejaculation
    • Receiving anal sex.
  • Enlarged prostate (benign prostate hyperplasia or benign prostatic enlargement). It is normal for your prostate to grow as you get older. If it gets too big, you may have problems passing pee.
  • Prostatitis. Sometimes, bacteria can get into your prostate. This causes your prostate to get inflamed.
  • Medicines. Some medicines can affect your PSA levels. Talk to your GP or nurse about your medicines before having the PSA test.
pills in a bottle
  • Other tests. If you have had a prostate biopsy, you will need to wait six weeks before having a PSA test. 
  • If the test result is ‘normal’ you may feel reassured.
  • It can help to pick up prostate cancer before you get any symptoms.
  • It can help to pick up fast-growing prostate cancer at an early stage. This means you can have treatment that could stop your cancer from spreading or causing problems.
  • It is not 100% accurate:
    • You may have a high PSA but not have prostate cancer
    • You may have a normal PSA but have prostate cancer.
  • You may have a slow-growing prostate cancer that would never have caused any problems or shortened your life. This can cause unnecessary worry and stress. 
  • If your PSA is raised, you may need other tests such as, a prostate biopsy. This can cause pain, infection and bleeding. 
  • You can speak to your GP. They will talk to you about your risk. 
  • There are risk calculators that can help you check your risk of prostate cancer. This can help you to decide whether to have a PSA test. 
  • Prostate Cancer UK have a risk checker (link will open in a new tab) that you can use online (this will open in an external tab). If this suggests that you may be at risk, come back to the infopool and visit our testing and diagnosis page (link will open in a new tab) to see what you can do next.

About this information

  • This information was published in March 2023. We will revise it in March 2024.
  • References and bibliography available on request.
  • If you want to reproduce this content, please see our Reproducing Our Content page (link will open in a new tab).

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