Why “Normal” Lab Test Ranges Don’t Equal Optimal Health
We’ve all had blood tests done, and the first thing most of us do is look at the range to see where our numbers fall. If we’re inside the range, we breathe a sigh of relief. But how often do we stop and ask what that range really means, or how it’s determined?
Doctors often say, “Everything looks normal, all within range,” and we assume that’s the end of the story. But normal doesn’t always mean healthy. These ranges are built on statistics, not on what’s truly optimal for the human body. Falling within the range only means your numbers look like those of the average population. And if the average population is already dealing with obesity, diabetes, or other chronic conditions, then “normal” may not be where you actually want to be.
What Is a Reference Range
A reference range is the benchmark a lab uses to decide if your test results are typical or unusual. But let’s break down what that really means.
How it’s set up
Labs collect results from a large group of people. From there, they calculate the average and then include the middle 95 percent of values. If your number falls inside that window, it’s reported as normal. If it falls in the outer 5 percent, you’re flagged as abnormal.What “normal” actually means
Normal doesn’t mean healthy. It doesn’t mean your body is working at its best. It simply means your number looks like most of the people in the reference group. If most of those people are metabolically unwell, then the definition of normal shifts in that direction.Adjustments for different groups
Labs sometimes create separate ranges based on age, sex, or even race. For example:A child will have a different normal range for hemoglobin than an adult.
Men and women often have different ranges for hormones or enzymes.
Some tests used to adjust for race, such as kidney function tests, although this is now being challenged as unnecessary and misleading.
So what you’re really seeing when you look at your test results is a comparison to a statistical group, not a measure of your true health.
Why Reference Ranges Can Mislead
Here’s where the real problem comes in. When the overall health of the population declines, so do the standards we use to measure what’s “normal.”
Chronic diseases like obesity, type 2 diabetes, and fatty liver are now so common that many people in the sample population have them. Their test results shift the averages upward or downward.
As more people become unhealthy, the normal range broadens or moves, meaning values once flagged as concerning may now be accepted as normal.
Doctors may not always look closely at where you fall within the range. Someone at the high end of normal might already be showing early dysfunction, even though the lab report still says “in range.”
This creates a dangerous gap between “normal” and “optimal.” Normal reflects the average health of a population that is struggling. Optimal means your body is functioning at its best.
What Is Optimal Health
So if “normal” isn’t good enough, what does optimal look like?
Optimal health is when your lab values fall into ranges that are linked with good energy, healthy metabolism, and low risk of disease. It’s not about being like everyone else. It’s about aiming for what the research shows supports vitality and long life.
Some examples:
Fasting glucose: Labs say 70 to 100 mg/dL is normal. But studies suggest being closer to 80–85 mg/dL is safer. Higher numbers, even within the “normal” range, can indicate early insulin resistance.
HbA1c: Normal is often listed as up to 6 percent. Yet many metabolic health experts suggest aiming for 5.0–5.4 percent, because higher levels increase your risk of complications.
TSH (thyroid hormone): Labs often say up to 4.5 is fine. But many endocrinologists believe anything over 2.5 may signal that the thyroid is under stress, especially if symptoms are present.
Vitamin D: Deficiency is flagged below 20 ng/mL, but many experts recommend 30–60 ng/mL for bone and immune health.
These examples show how the gap between “normal” and “optimal” can leave people believing their health is fine when it may already be trending downward.
What Experts Say
Doctors who focus on metabolic health often speak about this gap.
Dr. Paul Mason has pointed out that many lab reference ranges are “completely out of whack” because they’re based on unhealthy populations. He argues we should set standards based on healthy, long-lived groups instead of averages pulled from sick populations.
Dr. Eric Westman reminds patients that lab values need to be interpreted in context. A number on its own means little without knowing your diet, lifestyle, symptoms, and other markers.
Bart Kay has highlighted how relying on statistical norms can blind both doctors and patients to the early warning signs of disease. He urges people to question whether “normal” is the right target.
These voices encourage us to think critically about our results rather than accept them at face value.
Taking Your Health Into Your Own Hands
When you get lab results back, you have a choice. You can accept “normal” at face value, or you can take a more active role and ask if those numbers truly reflect optimal health. This is where being proactive makes all the difference.
Ask better questions. If your doctor says your results are normal, don’t stop there. Ask what the optimal range is and how close you are to it. Push for more than reassurance; push for clarity.
Watch the trends. One test doesn’t tell the full story. Look at your results over time. If your fasting glucose or thyroid numbers are creeping upward year after year, even within the “normal” range, that’s a sign worth paying attention to. Early action is far easier than waiting until there’s a diagnosis.
Look at the whole picture. A single number never defines your health. Your diet, sleep, stress, family history, and symptoms all matter. For example, normal cholesterol may not be reassuring if your triglycerides are high or your waistline is expanding.
Educate yourself. Learn what experts in metabolic health like Dr. Paul Mason and Dr. Eric Westman recommend. Compare their perspective with what your lab prints as “normal.” The more informed you are, the better questions you’ll ask, and the better care you’ll receive.
Act on what you learn. Numbers are feedback. Use them. If you see your vitamin D is low, consider more sunlight or supplementation. If your fasting glucose is climbing, rethink your carb, sugar and processed food intake. Small, consistent changes in food, sleep, and activity can bring you closer to optimal, not just average.
Taking ownership of your health doesn’t mean dismissing your doctor. It means working alongside them with more awareness and asking for more than “you’re normal.” You deserve to know where you stand, and you deserve to aim higher than average.
Why This Matters
If you accept “normal” as good enough, you end up living with the same risks that most of the population faces. And let’s be honest, most of the population is not thriving. Rates of diabetes, heart disease, fatty liver, and even early cognitive decline are climbing every year. Do you really want to measure yourself against that standard?
This is why being proactive matters. Knowledge is power. The more you understand how reference ranges are created and how they differ from what’s truly optimal, the more control you gain over your own health. Questioning things isn’t being difficult, it’s being wise. It means you care enough about your future to look deeper.
You don’t need to accept average as your goal. Average is where problems begin. Instead, aim higher. Ask better questions. Track your results over time. Learn what healthy populations and experienced physicians call optimal, and see how your numbers compare.
Your health is yours to protect. Don’t hand over that responsibility without thought. Use every test, every number, as a tool to get closer to the energy, clarity, and longevity you deserve.
Disclaimer: The content shared here is for informational and educational purposes only and should never be taken as medical advice.
In writing this blog post, my goal is to distill research findings into a clear, approachable format that encourages critical thinking and empowers you to make informed decisions about your health.
