PSA — What the Test Does and Does Not Settle
PSA screens for prostate cancer but cannot show what is causing an abnormal level. Screening and the treatment it can lead to may cause more harm than benefit for many men — a shared decision, not a box to tick.
A PSA test measures a protein made by the prostate and is used to screen for prostate cancer — but on its own it cannot show what is causing an abnormal level. There is genuine debate over its value: for many men, screening and the treatment it can lead to may cause more harm than benefit, which is why this is a shared decision with a clinician rather than a box to tick.
The biomarker
- Name: Prostate-Specific Antigen (PSA)
- Units: ng/mL
- Standard range: laboratory-specific (ranges vary by lab); under 4 ng/mL is generally considered normal, and a lower cut-off is sometimes used under age 50 — but current guidance emphasises shared decision-making over any single number.
How to read your result
| Pattern | What it means |
|---|---|
| What it measures | PSA in blood, produced by prostate cells — the test cannot tell cancer from noncancerous causes. |
| A normal PSA | Does not exclude prostate cancer: some men with prostate cancer do not have a raised PSA, and most men with a raised PSA do not have prostate cancer. |
| Raised, non-cancer causes | An enlarged prostate (BPH), prostatitis and other prostate problems, recent ejaculation, and catheterization or a recent urinary procedure can all raise PSA without cancer being present. |
| Free-PSA percentage | A follow-up test that measures the share of PSA not bound to proteins; a lower percentage makes prostate cancer more likely. |
| Trend over threshold | A biopsy may be recommended if PSA stays high or keeps rising on repeat tests — no single value should be read as an action trigger on its own. |
What moves the needle
- If raised, do not panic and do not act alone. Ask your clinician whether and when to repeat the test.
- Before testing, avoid ejaculation for 24 hours before the draw, and do not test soon after a urinary infection or a urinary procedure — mention either to your clinician.
- Decide with a clinician whether to test at all, based on your age, family history and how you weigh the trade-off.
Why this test is worth asking for
- Screening can find cancers that would never have caused harm; the resulting biopsies and treatments carry their own risks — the real trade-off worth understanding before testing.
- Family history of prostate cancer and Black ancestry both shift the risk calculation and are worth raising explicitly with a clinician.
Sources
- MedlinePlus — Prostate-Specific Antigen (PSA) Test
- MedlinePlus — Prostate Cancer Screening
- MedlinePlus — PSA blood test
AgeGen lab guides are educational only. We do not provide medical diagnosis, prescribe brands, or recommend specific doses. Talk to a licensed clinician before changing your supplement or medication routine.
