Lab Tests

PSA (Prostate-Specific Antigen)

The main screening marker for prostate health. One number can't tell the whole story — here's how to read it properly.

Men's healthBlood test4 min read

PSA is a protein made by your prostate. Levels rise with prostate enlargement, infection, or cancer. It's the primary screening tool for prostate cancer in men over 50, but interpreting it requires context — not just a cutoff number.

Optimal range
<2.5 ng/mL (under 50) · <4.0 (50+)
Why it matters
Prostate cancer screening
How often to test
Annually for men 50+ (45+ if high risk)
Fasting required?
No
Dive deeper into the science

What is this test?

PSA is a protein produced by both normal and cancerous prostate cells. A small amount leaks into your blood, and that's what the test measures. The key thing to understand: PSA is prostate-specific, not cancer-specific. Many things besides cancer raise it.

That's why a single PSA number doesn't tell you much on its own. What matters more is the trend over time (PSA velocity), your age, prostate size, and whether there are other symptoms.

What your number means

PSA levelWhat it suggests
< 1.0 ng/mLLow risk — can extend screening interval to every 2–3 years
1.0–2.5 ng/mLNormal for most men — annual monitoring
2.5–4.0 ng/mLGrey zone — consider free PSA ratio, age, and velocity
4.0–10.0 ng/mLElevated — about 25% chance of cancer. Urologist referral
> 10.0 ng/mLSignificantly elevated — about 50% chance of cancer. Urgent workup
Before your test

Avoid ejaculation for 48 hours, vigorous cycling for 48 hours, and intense lower-body exercise for 24 hours before your blood draw. These can all falsely elevate PSA.

How to support prostate health

Track your PSA velocity over time

A single PSA is a data point. eterni shows you the trend — so you and your doctor can spot changes before they become problems.

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Frequently Asked Questions

At what age should I start PSA screening?

Most guidelines recommend discussing PSA screening starting at age 50 for average-risk men. If you have a first-degree relative with prostate cancer or are of African descent, consider starting at 45. Some longevity-focused physicians recommend a baseline PSA at 40 to establish your personal trend.

Does a high PSA always mean cancer?

No. Most men with elevated PSA do not have prostate cancer. Common non-cancer causes include benign prostatic hyperplasia (BPH), prostatitis (infection/inflammation), recent ejaculation, vigorous cycling, and urinary tract infections. Only about 25% of men who undergo biopsy for elevated PSA are found to have cancer.

Can exercise or sex affect PSA?

Yes. Ejaculation can raise PSA for 24–48 hours. Vigorous cycling can elevate it through direct prostate compression. Intense lower-body exercise may also cause a transient bump. Avoid ejaculation for 48 hours and vigorous exercise for 24 hours before your blood draw for the most accurate result.

What is PSA velocity?

PSA velocity is the rate of PSA change over time, measured in ng/mL per year. A rise of more than 0.75 ng/mL per year is concerning even if the absolute PSA is within the normal range. This is why tracking PSA over time is more valuable than a single reading — it reveals the trajectory.

Research & Science

Free PSA and PSA density

When your total PSA is in the grey zone (2.5–10 ng/mL), two additional calculations help distinguish cancer from benign causes:

India-specific context

Know what's working. Know what's not.

eterni connects your lab results, supplements, and retests — so you can see the trajectory, not just a snapshot.

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