What is the PSA test?

The PSA (Prostate-specific antigen) test is a blood test. Used with other tests it can help doctors diagnose prostate cancer.

PSA is a protein made in the prostate gland. Some PSA leaks into the blood and can be measured in a test. A small amount of PSA in the blood is normal.

If the prostate becomes enlarged, inflamed, or infected, larger amounts of PSA get into the blood. The amount of PSA in the blood may also increase if there is cancer in the prostate.

A raised PSA level may be a sign of prostate cancer. But it can also be caused by other things, such as non-cancerous prostate conditions.

Who can have the PSA test?

If you are over 50, you can ask your GP for a PSA test. GPs do not routinely offer PSA testing as part of a general health check, or if you do not have any symptoms.

If you ask for a PSA test, your GP will advise you to think carefully about the benefits and disadvantages.

If you have a higher risk of prostate cancer, it is important to talk to your GP about your personal risk. This is even if you do not have any symptoms. Early prostate cancer does not usually cause symptoms.

Talking to your GP can help you to make an informed decision about having a PSA test.

If you are transgender

People who have a prostate include men, transgender (trans) women and people assigned male at birth. If you are a trans woman and have had genital gender affirming surgery as part of your transition, you will still have a prostate. It is important to talk to your GP or nurse if you are worried about prostate cancer or have symptoms and want to have the PSA test.

If you find it difficult to start the conversation, you could try showing them our information on transgender and cancer.

Is there a national screening programme for prostate cancer?

Screening is a way to try to find cancer early in people who do not have any symptoms. In the UK, there are screening programmes for breast, bowel, and cervical cancer.

There is no UK national screening programme for prostate cancer. The PSA test on its own is not accurate enough to be used in a screening programme to diagnose early prostate cancer. It may falsely diagnose prostate cancer and may also miss some cancers.

Some studies show that lives may be saved by PSA screening because it may lead to prostate cancer being diagnosed at an early stage. But they also show that screening may lead to:

  • more invasive tests, such as a prostate biopsy, which can cause complications
  • more treatment of slow growing prostate cancers that would never have caused serious harm.

Treatment side effects include:

  • urinary incontinence
  • bowel problems
  • or difficulty getting an erection.

For a screening programme to be effective, the benefits need to outweigh the disadvantages.

Why a PSA test is done

The PSA test may help to diagnose very early prostate cancer before any symptoms develop. But there are benefits and disadvantages of having treatment for early prostate cancer.

Sometimes a PSA test can lead to an earlier diagnosis of prostate cancer, when treatment to cure the cancer could be more effective. This is particularly the case if you have higher risk factors of prostate cancer.

Some prostate cancers grow very slowly. With early prostate cancer, you are not likely to die from it within the next 10 years. For some people, the possible side effects of treatment may be worse than the effects of the cancer itself.

You may decide you do not want to know if you have prostate cancer because of the anxiety or uncertainty it might cause you. You may not want further tests, or to make difficult decisions about treatment. Or you may have concerns about the side effects of treatment. Some treatment for prostate cancer may cause urinary incontinence or bowel problems, or affect your ability to get an erection.

  • If you have risk factors

    It is important to talk to your doctor about any risk factors when discussing a PSA test. You should be able to get PSA test from the age of 50. But if you have higher risk factors of prostate cancer you should be able to get it from 45 or younger. For example:

    • if you are a black man your risk of prostate cancer is much higher
    • if you have a family history of prostate cancer and breast cancer your risk is also higher.

    With both these risk factors prostate cancer may happen at an earlier age.

  • If you have symptoms

    You may want to have a PSA test if you have urinary symptoms, such as trouble peeing (passing urine) or peeing often, or erection problems. But these are often caused by common non-cancerous prostate problems (see below) and not prostate cancer.

  • Talk to your doctor

    There is no right or wrong answer about whether to have the PSA test. Before you decide, talk to your GP or hospital doctor about it.

    It may be helpful to make a list of questions before your appointment. Your doctor will explain the benefits and disadvantages to having the PSA test. They can help you make a decision that is right for you.

Having the PSA test

If you decide to have the PSA test, your GP or nurse will take a blood sample. They send it to a laboratory to be tested. You can ask how long the result will take.

If you are having the PSA test, you usually have a rectal examination as well. The doctor gently inserts a gloved finger, using lubricating gel, into your back passage (rectum) to feel the prostate. It may be uncomfortable, but it is quick and should not be painful.

PSA test results

There is not one normal PSA level for everyone. The PSA level naturally gets higher as you get older and varies depending on the size of your prostate. The size of the prostate is different for everyone and the prostate also gets bigger with age. There are different things that can affect the PSA level, for example, non-cancerous prostate problems or a urine infection.

Hospitals may have normal ranges for PSA testing based on age, but they do not consider all these other factors.

What is a normal PSA level?

Your GP will think about different things when assessing the results of your PSA test. They will tell you if they think your PSA result is higher than it should be for your age and situation.

PSA is usually measured in nanograms per millilitre of blood (ng/ml). If your PSA level is, for example, 3 ng/ml or higher (depending on your age and situation), you may be referred to see a specialist. Or your GP may recommend repeating your PSA test in a few weeks.

If you have risk factors for prostate cancer you may be referred to a specialist even with a lower PSA.

One PSA test result is not reliable on its own. Having a high PSA level does not mean you have prostate cancer. But the higher the PSA level, the greater the chance of prostate cancer. A continuous rise in PSA level over time may also be a sign of prostate cancer.

A normal PSA level does not mean you will never get prostate cancer. Sometimes prostate cancer can be present even when PSA levels are lower.

Prostate conditions that can affect PSA levels

Different things other than prostate cancer can raise PSA levels. This includes common prostate conditions, such as:

  • benign prostatic hyperplasia (or hypertrophy) called BPH for short
  • prostatitis (inflammation of the prostate).

BPH and prostatitis can both cause a raised level of PSA in the blood, but they are not prostate cancer.

  • Benign prostatic hyperplasia (BPH)

    This is when the prostate increases in size. It is part of the normal ageing process and is common over the age of 50.

    Symptoms of BPH can include:

    • difficulty starting to pee (pass urine)
    • having a weak flow of pee
    • needing to pee more often than usual, especially at night
    • feeling like you have not completely emptied your bladder
    • an urgent need to pee.
  • Prostatitis

    This is when the prostate is inflamed, usually because of an infection. It can also be caused by injury to the prostate, or by some autoimmune diseases. Autoimmune diseases cause the body’s immune system to damage healthy cells in the body. Prostatitis may not cause any symptoms, but symptoms can include:

    • repeated urine infections – these can be treated with antibiotics
    • pain in or around the end of the penis, testicles, inner thighs, the area between the testicles and back passage (perineum) or the lower back
    • pain during ejaculation, or blood in the ejaculated semen.

What else can affect a PSA level?

There are some situations where PSA levels can be raised for a short while. These may affect how accurate the test result is. If you decide to have the PSA test, your doctor may suggest you wait for a while if any of the following apply to you.

Things that can raise a PSA level are:

  • urine infections
  • recent ejaculation (within the last 48 hours)
  • having a tube in your bladder to drain pee (urinary catheter)
  • recent prostate biopsies
  • prostate or bladder surgery
  • exercising energetically 48 hours before the test (some doctors include cycling in this advice)
  • receiving anal sex or prostate stimulation during sex (it is best to avoid this for 1 week before the PSA test).

Some medicines that help with urinary symptoms caused by BPH can lower the PSA level in your blood. They include:

  • finasteride (Proscar®)
  • dutasteride (Avodart®, Combodart®).

If you have the PSA test, always tell your GP or nurse about any medicines you are taking. This includes ones you buy over the counter, complementary therapies or drugs made from herb and plant extracts.

What happens after the PSA test?

This depends on the results of the PSA test and the rectal examination. If both the PSA level and the rectal examination are normal, you will not need any more tests.

If your PSA level is raised but your prostate feels normal, your GP usually checks your PSA level again. They will then refer you to a specialist.

Your GP will talk to you about seeing a specialist if either:

  • your PSA level is raised
  • your prostate feels abnormal.

Seeing a specialist

You will usually be seen within 2 weeks of your GP making a referral. The specialist will talk to you about having a specialised scan called a multi-parametric MRI scan.

Depending on the results of your scan your doctor may:

  • explain that you do not need any further tests
  • ask you to think about having a prostate biopsy.

Before a biopsy your specialist doctor will explain the risks and benefits to help you to decide. If you have prostate cancer, your specialist will talk to you about your options.

Benefits and disadvantages of having the PSA test

It can help to think about the possible benefits and disadvantages before having a PSA test. You can talk these over with your GP or nurse as well as checking if you have any risk factors for prostate cancer.

Possible benefits

  • You may feel reassured if the PSA result is normal.
  • If your PSA level is raised, you can continue to have it monitored.
  • It can help, along with other tests, diagnose prostate cancer early when treatments may cure it or help you to live longer.

Possible disadvantages

  • If your PSA level is raised, you may feel anxious.
  • It is possible to have a normal PSA level and still have prostate cancer.
  • If your PSA level is raised you may not have prostate cancer but will need further tests, which may include a biopsy.
  • If you are diagnosed with prostate cancer, you need to make decisions about treatments.
  • Treating early prostate cancer may not help you to live for longer and the side effects of treatment can affect your quality of life.

Questions to think about

Deciding whether to have the PSA test can be hard. Thinking about what is important to you can help you make the best decision. You could think about the following questions:

  • What would you do if your PSA level is raised?
  • What would you do if further tests find that you have early prostate cancer?
  • What difference will it make for you to know about an early prostate cancer?

About our information

  • Reviewers

    This information has been written, revised and edited by Macmillan Cancer Support’s Cancer Information Development team. It has been reviewed by expert medical and health professionals and people living with cancer. It has been approved by Senior Medical Editors, Dr Jim Barber, Consultant Clinical Oncologist and Dr Ursula McGovern, Consultant Medical Oncologist.

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