What Your Lab Results Aren’t Telling You

By Centered on Wellness | St. Simons Island

Many patients know the feeling: a doctor’s visit ends with a stack of lab results, all stamped “normal,” and yet something still feels off. Fatigue lingers. Focus slips. The only answer offered is that this is simply part of getting older.

According to Dr. Diane Bowen of Centered on Wellness, that response overlooks an important distinction — the difference between a “normal” lab result and an “optimal” one.

“A normal range isn’t a measure of how you should feel,” Dr. Bowen said. “It’s a statistic.”

How “normal” is defined

Reference ranges, the numbers doctors use to determine whether a lab result falls in typical territory, are built by testing a group of people who are considered healthy and identifying where the middle 95 percent of their results fall. Definitions can vary by lab, by medical society and even by country.

By design, that method means roughly one in 20 healthy people will land outside the standard range simply due to natural variation. At the same time, some people whose numbers fall inside the range may already be dealing with an underlying issue, while others outside it may be perfectly healthy.

Dr. Bowen compares it to a school grade. If a child capable of scoring a 92 on a math test instead earns a 72, no one would call that a success just because it’s a passing grade. The number alone doesn’t tell the whole story — and the same, she said, is true for many lab results.

Part of the challenge, according to Dr. Bowen, is that most adults don’t have detailed lab records from their healthiest years to use as a personal baseline for comparison. And because metabolic issues are increasingly showing up earlier in life, even a “healthy” child today may be dealing with problems that haven’t surfaced yet.

Why deeper testing isn’t standard

If normal ranges are imperfect, why doesn’t routine care dig further? Dr. Bowen said the answer usually isn’t a lack of attention from physicians — it’s the structure of the health care system itself.

Screening guidelines generally require solid evidence that catching a problem early, in someone without symptoms, actually leads to a better outcome before that testing becomes routine. Insurance coverage for additional testing often depends on a specific, documented diagnosis code already being on file. And primary care appointments are short, averaging around 20 minutes, with some practices limiting visits to a single health concern.

The result, Dr. Bowen said, is a system that can end up treating a lab value rather than the person behind it.

She points to a few examples from recent research. One national study found that serum magnesium levels can significantly underestimate true magnesium needs in critically ill patients, even though magnesium plays a role in more than 300 enzyme processes tied to metabolic health. Separately, some research on thyroid function suggests that people with classic symptoms of an underactive thyroid, including weight gain, hair loss and constipation, are sometimes dismissed because their standard thyroid test, known as TSH, still falls in the normal range.

Meanwhile, national data show roughly a quarter of women over 60 are taking an antidepressant. Dr. Bowen said that statistic raises a question worth asking more often: how many of those cases might trace back to an unaddressed physical cause, such as low thyroid function, or a deficiency in magnesium, B12 or vitamin D, rather than a purely mental health issue.

What patients can do

Dr. Bowen offers a few starting points for anyone who has been told their labs look fine but still doesn’t feel like themselves.

First, treat symptoms as data. Fatigue, brain fog and mood changes are worth investigating rather than dismissing.

Second, ask not just whether a result is “in range,” but where in the range it falls — near the center, or toward the high or low edge.

Third, understand that broader testing, such as a fuller thyroid panel, fasting insulin or magnesium studies, isn’t about chasing every possible number. It works best when it’s guided by a clear question, combined with a person’s history and symptoms, and paired with a plan for what to do with the results. Current medications can also affect nutrient levels, and in turn, mood, she noted.

A different kind of conversation

At Centered on Wellness, Dr. Bowen said, these are the conversations she and her team most enjoy having with patients — looking at the whole picture rather than a single checked box.

“If you’ve been told your labs are fine but you don’t feel fine, it might be worth a deeper look together,” she said.

Those interested in a more personalized look at their own results can reach out to Centered on Wellness to schedule an assessment.