PSA (Prostate-Specific Antigen)

What is PSA

PSA (Prostate-Specific Antigen) is a protein produced by prostate gland cells. A small amount of PSA always enters the bloodstream and is therefore detectable in a blood test. PSA is most commonly tested in men as a marker of prostate health.

PSA is not a cancer indicator — it is an indicator of prostate activity. An elevated PSA can reflect benign prostate enlargement, inflammation, or an oncological process. For this reason, a PSA result must always be interpreted together with a doctor.

Along with total PSA, free PSA (f-PSA) is often tested as well. Their ratio helps the doctor assess the situation more precisely.

Reference Ranges

The most commonly applied threshold for men is up to 4.0 ng/mL. However, this threshold is a guideline: some laboratories apply stricter norms for younger men (e.g., up to 2.5 ng/mL under age 50). The reference range stated by the laboratory is always the most important.

PSA is not typically tested in women, as they do not have a prostate gland (though minimal amounts may be detected).

Units: ng/mL (nanograms per millilitre).

Why PSA May Be Elevated

An elevated PSA can be associated with various causes:

• Benign prostatic hyperplasia (BPH) — the most common cause in men over 50. An enlarged gland produces more PSA.
• Prostatitis (prostate inflammation) — bacterial or non-infectious inflammation can significantly raise PSA.
• Prostate cancer — an oncological process can increase PSA, but not every elevated PSA means cancer.
• Physical factors — intense cycling, sitting on a hard surface, bladder catheterisation, or prostate massage can temporarily raise PSA.
• Age — PSA naturally increases slightly with age.

Why PSA May Be Low

A low PSA is generally not a cause for clinical concern. Certain factors can lower PSA:

• 5-alpha reductase inhibitors (medications for prostate enlargement) — can reduce PSA by approximately half.
• Obesity — research suggests that an elevated body mass index can lower PSA due to haemodilution (a dilution effect in the blood).
• Young age — PSA is naturally low in young men.

What to Do Next

If your PSA is elevated — do not panic, but do not ignore it either. A single elevated result is not a diagnosis. Your doctor may recommend:

• Repeating the test after a few weeks (to rule out temporary causes).
• Additionally testing the free PSA to total PSA ratio.
• Performing a prostate ultrasound or other investigations.

Before the test, it is recommended to avoid intense physical exertion and sexual activity for 48 hours, as these can affect the result.

Monitoring Over Time

A PSA value is more informative when tracked as a trend than when assessed as a single measurement. An important indicator is PSA velocity (how much PSA increases per year). A sudden rise is a more significant signal than a stably slightly elevated level.

For men from age 50 (or from age 40–45 if there is a family history of prostate cancer), periodic PSA testing is recommended according to the doctor's guidance.

Questions for Your Doctor

1. Does my PSA level correspond to the normal range for my age? 2. Should the free PSA to total PSA ratio be tested? 3. How often should I repeat the PSA test? 4. Can any medications I am taking affect the PSA result? 5. Are there reasons to carry out additional prostate investigations?

*This is not medical advice. For decisions regarding your health, consult your doctor.*