The London Clinic, 120 Harley Street, London, W1G 7JW


If your doctor has recommended a PSA test then you might be wondering what exactly this test will be measuring. Keep reading to find out what PSA is and what might be affecting your PSA test results.

PAS Test for Prostate Cancer

What is PSA?

Prostate Specific Antigen or PSA is a protein that is made in the prostate gland. It is actually an enzyme that helps to break certain other proteins down in order to ensure that semen has the correct consistency. PSA therefore plays an important role in your reproductive system.

Most of the PSA that you produce will stay inside the prostate, but some of it can leak out into your bloodstream. The amount of PSA in your blood is related to the amount that your prostate is producing, so we can measure it to find out what is going on with your prostate gland.

The PSA Test

You are most likely to hear about PSA if you visit your doctor for prostate cancer screening or because you have symptoms of an enlarged prostate (such as urinary problems). The PSA test is a blood test that measures the amount of PSA that is circulating in your body. Your doctor may recommend the PSA test to find out if your prostate is producing more PSA than usual. If your prostate is producing high levels of PSA then more of it will escape into the bloodstream. If it is, this could be due to prostate cancer However, there are other reasons why your PSA test result may be higher than expected that are not due to cancer.

What Affects PSA Levels?

The reason why we test your PSA levels is that it can be a sign of prostate cancer. It can also indicate an enlarged prostate. However, the PSA test isn’t the only result we use to check for these conditions. High PSA levels aren’t always connected to prostate problems and these conditions don’t always cause changes in your PSA levels.

Common causes of high PSA levels are:

  • Benign prostate enlargement
  • Prostate cancer
  • An infection

If you have one of these conditions, then you may need treatment your doctor will need to run other tests to confirm the diagnosis, and the treatment approach will also depend on what symptoms you’re experiencing. In cases when prognosis is good and the condition can be safely monitored, treatment may not always be necessary; however it is important that you follow medical guidance.

PSA levels may also be temporarily higher than normal if:

  • You have had sex or ejaculated in the last 48 hours
  • You exercised strenuously in the last 48 hours
  • You have had any kind of a prostate manipulation such as surgery or biopsy in the last 6 weeks

Your doctor will therefore recommend that you avoid these activities for a while before your PSA test or ensure that your blood sample is taken before any other tests that could interfere with the results.