🩺 Conventional vs. Functional Ranges: What’s the Difference?

Most doctors use what’s called the conventional range — the range established by large population averages. It’s the standard used in our current medical system, and it’s helpful for identifying disease states. If your numbers fall outside that range, something is likely wrong and needs medical attention.

But here’s the catch: those ranges are often based on the average population — and average doesn’t always mean healthy.

Functional ranges are different. They’re used by functional and integrative medicine practitioners, longevity experts, and many forward-thinking MDs. Instead of asking, “Are you sick?”, functional ranges ask:

👉 “Are you operating at your best?”

They reflect the levels at which systems in the body function optimally — where inflammation is lower, energy is higher, cognition is sharper, and long-term disease risk is reduced.

Here’s a simple way to think of it:

• Conventional range: “You’re not empty.” (The gas tank isn’t dry.)

• Functional range: “You’re fueled to go the distance.” (The tank is topped up for performance.)

This difference is why your doctor might say your vitamin D is “normal” at 32 — while a functional practitioner will tell you it’s suboptimal and needs support to reach 60–80, where immune and metabolic health thrive.

💡 In short: Conventional ranges keep you from falling into disease. Functional ranges aim to keep you out of the slow slide toward disease in the first place.