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Prostate-specific antigen (PSA)

Prostate cells produce a substance called prostate-specific antigen (PSA). This substance is only produced by prostate cells. It is usually found in small amounts in the blood of men. However, PSA concentrations in the blood may be increased in certain situations.

What is the purpose of this test?
  • Help diagnose prostate cancer
  • Monitor the progression of prostate cancer and the effectiveness of treatment
How to prepare? Avoid ejaculation 48 hours before the test.
Reference values* Total PSA: < 4="">
Associated tests Certain tests may be associated, such as:
  • a digital rectal exam
  • a prostate biopsy
How is it done? A blood sample is drawn, usually from a vein in the arm.
How long before I get the results? Results are usually ready in one or two days. It may take longer to receive your results.
* These values are presented for information purposes only. As different laboratories may have different target values, the lab report usually specifies the values used for the test. It should also be noted that test results must be interpreted based on factors such as age, sex, and health condition. Values outside of this range may be considered normal for some individuals.

What does an abnormal test result mean?

High values of PSA:

  • prostate infection or inflammation (prostatitis)
  • benign prostatic hyperplasia
  • prostate cancer

Medications that may affect test results

The use of certain medications can influence test results. Here are a few examples:

Low values of PSA:

  • finasteride
  • dutasteride

Factors that can affect the result of the test

PSA results may be increased by:

  • age (older men usually have higher PSA results)
  • a recent digital exam or prostate procedure
  • a urinary tract infection
  • vigorous sports (e.g., bike riding)

What you should know before going for this test

When you go in for a blood test or any other medical exam, it's always a good idea to bring a complete list of any prescriptions, over-the-counter medications, or natural health products you're taking. Unless otherwise advised, it's best to take your medications as usual on blood test days. If in doubt, don't hesitate to talk to your healthcare professional.

© Copyright Vigilance Santé

The patient information leaflets are provided by Vigilance Santé Inc. This content is for information purposes only and does not in any manner whatsoever replace the opinion or advice of your health care professional. Always consult a health care professional before making a decision about your medication or treatment.

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