The PSA Test: What It Means, What It Doesn't, and How to Read the Number

The PSA (prostate-specific antigen) blood test is one of the most-ordered, most-discussed, most-controversial tests in midlife men's health. Almost every man over 50 will have at least one PSA test ordered by their GP. Very few of them have had a real conversation about what the test is actually for, what its limitations are, and how to read the result in context.

This article is what we'd want a man to know going into his first PSA test.

What PSA actually measures

PSA is a protein produced by the prostate gland. Some of it leaks into the bloodstream in healthy conditions; more of it leaks under various non-healthy conditions. The blood test measures the concentration in nanograms per millilitre.

What it's really measuring is "how much PSA is in your blood," which is a proxy for "what's happening in your prostate." It does not directly detect cancer. It does not directly detect BPH. It detects elevated PSA, which can be caused by many things.

The four things that elevate PSA

1. Prostate cancer — the headline concern, but not the only one.
2. Benign prostatic hyperplasia (BPH) — enlarged prostate produces more PSA. Roughly half of men over 60 have BPH; their baseline PSA is typically higher than younger men's.
3. Prostatitis — inflammation of the prostate, often from infection.
4. Recent prostate manipulation — DRE within 24 hours, recent ejaculation, recent cycling, recent prostate biopsy. All can transiently raise PSA.

The PSA test itself can't distinguish between these. That's its biggest limitation.

How to read the number

Rough age-adjusted PSA ranges (different labs give slightly different cutoffs):

• Under 50: below 2.5 ng/mL is typical normal range
• 50-59: below 3.5 ng/mL
• 60-69: below 4.5 ng/mL
• 70+: below 6.5 ng/mL

But — and this is important — the trend matters more than any single number. A man whose PSA went from 1.2 to 1.5 to 1.9 over three years, all within "normal range," may be telling a more concerning story than a man whose PSA was 4.0 last year and 4.0 this year. Velocity of change is one of the most useful signals.

Other context matters too: PSA density (PSA divided by prostate volume), free-to-total PSA ratio (lower free-to-total PSA is more concerning), and family history. A modern PSA conversation considers all of these together, not just the headline number.

The over-diagnosis problem

Here's the genuine controversy. Prostate cancer is unusual among cancers in that many men have it, but most of the men who have it never know — because most prostate cancers are slow-growing and never become clinically significant during the man's lifetime. Studies of autopsies in men who died of unrelated causes find prostate cancer in roughly 30% of men in their 50s, 50% in their 70s, and 80% in their 80s. Most of them never had symptoms.

This creates a real dilemma: PSA-driven screening detects many of these slow-growing cancers, leading to biopsies, treatments, and side effects (incontinence, erectile dysfunction, surgical complications) for cancers that would never have hurt the man if left undetected.

The pendulum on PSA screening has swung over the last two decades — initial enthusiasm in the 1990s, growing scepticism in the 2000s, and a more nuanced "shared decision-making" framework in current guidelines. The current consensus in most countries is:

• PSA testing should be offered, not pushed, for men 50-70 with average risk.
• Earlier and more aggressive testing for high-risk men (Black men, family history, BRCA mutations).
• Decisions about biopsy and treatment should consider age, life expectancy, and risk profile, not just PSA.

What to ask your GP

Before having a PSA test, the conversation worth having:

1. Why is this test being recommended now? (Routine screening, symptoms, family history, etc.)
2. What's my baseline risk profile? (Age, ethnicity, family history.)
3. If the result is abnormal, what's the next step? (Repeat in 6-12 weeks, free-PSA test, MRI, biopsy.)
4. How will we interpret the result in context? (Single number vs. trend, age-adjusted ranges, density.)
5. What's my preference for trade-off between detection and over-diagnosis?

You're not obligated to have a PSA test. You're also not obligated to refuse one. The right answer depends on your specific situation, and the conversation should be a real conversation, not a 30-second checkbox.

Saw Palmetto and PSA

One specific question we get from ProstaRemedy customers: does Saw Palmetto interfere with PSA testing? The honest answer: probably not in any clinically meaningful way. Unlike finasteride and dutasteride, which dramatically lower PSA (by roughly 50%) and require interpretation adjustments, Saw Palmetto's effect on PSA is minimal in the published literature.

That said, if you're undergoing PSA monitoring, mention any supplements you're taking to your doctor so they can interpret results in context.

The honest summary

The PSA test is a useful but imperfect signal. Read it in context — age, trend, density, family history — rather than as a single yes/no answer. Have a real conversation with your GP about whether and when to test, and what to do with the result.

Don't be the man who hands the decision over without engaging with it. It's your prostate.