Lab reference ranges describe the population. They aren't the bar.

My last full panel came back with green checkmarks down the right margin — every value “in range.” The portal summed it up in one line: No abnormal results detected. I told my wife everything looked fine, closed the email, and only went back and read the actual numbers later.

Three of them I’d have flagged if they belonged to someone I cared about.

Here’s where a reference range comes from. The lab takes tens of thousands of people who came in for blood work last quarter, drops the bottom 2.5% and the top 2.5%, and calls the middle 95% “normal.” That’s the whole method — it’s a percentile of the lab’s own foot traffic. And that foot traffic is whoever the lab serves: a mix of pre-diabetic, inflamed, sedentary, stressed, otherwise-average adults. So “in range” means not statistically unusual among the people who got blood drawn last quarter. It does not mean optimal for anyone in particular — and it certainly doesn’t mean optimal for a 35-year-old who lifts five days a week.

A few of the markers I track, lab “normal” against what the evidence-based literature targets for an active adult:

A fasting insulin of 12 is in range. It’s also more than double the optimal target. An HbA1c of 5.5 is in range. It’s also closer to pre-diabetic than to metabolically healthy. The portal green-checks both, a busy PCP scrolls past both, and you don’t learn anything was off until the slow drift finally crosses some harder line years later and gets a name.

Let me be clear about what I’m not claiming. The right-hand column isn’t settled. The Vitamin D target moves depending on whose meta-analysis you read. The fasting-insulin number is tighter in the functional-medicine literature than in mainstream endocrinology. hs-CRP under 1.0 is a Cleveland-Clinic-adjacent threshold, not a law of nature. Reasonable people argue about every row by 10–30%.

What I am claiming is narrower: “normal” and “good” are different questions, and the lab only answers the first one.

The thing that actually changed how I read a panel was treating each marker as a time-series, not a one-off verdict from an authority. A single value tells me where a thousand strangers landed last week. What I care about is where my HbA1c sat last year, and whether the slope I’m on at 35 lands me somewhere ugly at 50. The portal shows one dot. The /health page on this site shows the line.

Either column in that table could be wrong. The lab one is built from people I’m actively trying not to become; the optimal one is an educated guess that good sources disagree about. Given the choice, I’d rather argue with the optimal numbers than ignore them.