Testing & Screening
Which tests change what you do — and which just find something to worry about.
Testing feels like the responsible thing to do, which is why it sells so well. But a test only helps if the result would change what you do, and a surprising number of popular tests can't clear that bar — while carrying real costs in false positives, incidental findings, anxiety and downstream investigation.
We run a blood-testing page ourselves, so we'll be direct: these pages exist to tell you when testing isn't indicated. No advertising or product recommendations appear anywhere in this section, by rule.
Guides
- Blood Panels: What's Worth Knowing
A short list of markers that change decisions, and why "optimal ranges" are usually somebody's marketing.
- Whole-Body MRI Scans: Why No Society Recommends Them
In asymptomatic people, nearly everyone has an "abnormal finding" — and the overwhelming majority mean nothing.
- At-Home Test Kits, Rated
Some are genuinely useful. Several are sold on findings the relevant professional bodies have explicitly rejected.