Sick Care, Well Care, and the Gap In Between

A thoughtful American physician wrote recently about a tension he couldn't fully resolve. He had trained to treat the sick. He had accepted, over time, a role in preventing sickness in the healthy. But he was increasingly being asked to do something else — to help people who weren't sick and weren't merely healthy but were somewhere in between, seeking interventions that sat outside his training, his evidence base, and his sense of what medicine was for.

He was honest about his discomfort. And his discomfort points to something real: the infrastructure of modern medicine, including its training, its diagnostic categories, its payment systems, and its evidence hierarchies, was built around a binary. You are sick, or you are not sick. If you are sick, we treat you. If you are not sick, we screen you for future sickness and counsel you on evidence-based behaviours. Everything outside that framework is, in his word, a hobby.

I understand the clinical conservatism. I share the scepticism about products sold on stories rather than data. But the binary itself is the problem. And it is causing significant harm to the people who fall into the gap it creates.

The sliding scale nobody mapped

Health is not binary. It never was. What we call sickness and what we call health are points on a continuum, and that continuum looks different for every person — different trajectories, different speeds of movement along it, different points at which the transition from functional decline to diagnosable disease finally becomes visible.

The acute end of the scale is where the medical system excels. If you are having a heart attack, the system will save your life with a speed and precision that is genuinely extraordinary. If you have an infection requiring antibiotics, the system provides them. Emergency medicine, surgery, intensive care — these are among the genuine triumphs of modern science, and I have no argument with them.

The optimising end of the scale is where the system becomes dismissive. The person running blood tests voluntarily, monitoring their sleep architecture, experimenting with nutrition, taking adaptogenic herbs and targeted supplementation — this person is labelled, at best, an enthusiast and at worst a fool. The physician who wrote the piece I read placed them in the category of "wellness hobbies" and withdrew from engagement. The concern is understandable: some of what is sold in this space is indeed without evidence. But the category error is significant. Monitoring your own biology, investigating your own patterns, and intervening proactively before symptoms become diagnoses is not a hobby. It is prevention. And the fact that it is not reimbursed or taught in medical school does not make it without value.

But the most underserved population is in neither of these places. It is the middle of that scale — the person who is symptomatic but not diagnosably sick. Fatigued but with normal bloods. Gaining weight despite reasonable diet. Gut that has never fully worked properly. Sleep that has deteriorated. Brain that doesn't feel quite right. Mood lower than it used to be, but not clinically depressed. Joints that ache. Energy that doesn't return after rest.

These people go to their GP. They have blood tests. The results come back normal. They are told there is nothing wrong with them, or given a prescription for a symptom — an antidepressant for the low mood, a PPI for the gut, a sleep medication for the insomnia. The underlying pattern is not investigated because the tools and training to investigate it are not part of standard care. They leave with a prescription and no answer, and they decline a little further before the next consultation.

What reference ranges are actually measuring

The laboratory reference range is a statistical construct. It is typically defined as the central 95% of values from a tested population — which means 2.5% of healthy people will fall outside the range on any given test even if nothing is wrong, and a substantial proportion of people within the range will have results that are suboptimal for their individual function.

More importantly, the populations used to establish reference ranges are not populations of verified healthy people. They include people with undiagnosed conditions, people on medications, people with nutritional insufficiencies and subclinical dysfunction that hasn't yet produced a clinical diagnosis. A reference range built from this population does not define health. It defines statistical normality within a population that includes a substantial proportion of unhealthy people.

Consider a TSH of 4.26. This sits within the standard laboratory reference range — perhaps 0.4 to 5.0 depending on the laboratory. The report says normal. But most functional medicine practitioners, and an increasing number of endocrinologists, regard a TSH above 2.5 as potentially indicating subclinical hypothyroidism worth investigating further. At 4.26, the thyroid is working harder than it should to maintain hormone output. The system calls it normal. The patient experiences fatigue, weight gain, poor recovery, and declining cognitive function — and is told their thyroid is fine.

A ferritin of 77 looks unremarkable on a standard panel. But if the iron saturation is 37% — below the functional threshold of 45% — the ferritin is being held up by inflammation while iron is not being delivered to tissue. The number in isolation is reassuring. The pattern tells a different story. The system, built to read numbers rather than patterns, misses it.

This is not a criticism of individual clinicians. It is a structural problem. The system was not built to look for these patterns, and clinicians trained in that system were not taught to find them.

The evidence asymmetry nobody talks about honestly

The standard objection to functional medicine and health optimisation is that the evidence base is insufficient. This is sometimes true and always worth taking seriously. But the objection is applied asymmetrically, and the asymmetry matters.

The evidence-based medicine standard, applied consistently and honestly, would require us to be sceptical in both directions. It would require us to note that Depo Provera — a widely prescribed contraceptive — has been linked to a significantly increased risk of meningioma, a brain tumour, with legal action currently ongoing in the United States and United Kingdom. It would require us to acknowledge the documented association between long-term proton pump inhibitor use and increased dementia risk — a finding that has received mainstream press coverage and which represents a significant public health concern given the tens of millions of people on these drugs globally. It would require sustained scrutiny of GLP-1 receptor agonists: the muscle mass loss that accompanies rapid weight reduction, the rebound weight gain on discontinuation, the gastrointestinal complications in a proportion of users.

None of these observations is an argument against pharmaceutical medicine. Statins prevent cardiac events. Antibiotics save lives. GLP-1 drugs have genuine clinical applications. The argument is simpler: the scepticism that is applied swiftly and categorically to ashwagandha or magnesium or a targeted nutritional protocol should apply with equal rigour to every pharmaceutical intervention. Safe and effective is a standard, not a given. And in the history of medicine, the consequences of assuming it were given have been severe and repeated.

Meanwhile, I am not aware of a documented body count attributable to people running voluntary blood panels and taking targeted supplementation based on their results. I am not aware of a public health crisis caused by people walking their dogs, practising qi gong, and eating more vegetables. The risk profile of proactive, informed, evidence-informed self-care is not the same as the risk profile of pharmaceutical intervention at scale, and treating them with equivalent scepticism requires a deliberate choice to ignore that difference.

Who the worried well actually are

The people who come to a functional medicine practice are rarely hobbyists in the dismissive sense. They are, more often, people who have been through the standard system and found it insufficient. They had symptoms. They had tests. The tests were normal. The symptoms continued. And they concluded — correctly — that the system was not going to find the answer they needed, and began looking elsewhere.

They are not the same as the person at the optimising end of the scale, though that person is also not the problem they are sometimes made out to be. Someone who wants to optimise their sleep, improve their metabolic function, understand their hormone patterns, and make informed decisions about their nutrition is not doing something dangerous. They are doing something sensible. The fact that it is not what medicine was designed for is a limitation of medicine's design, not a character flaw in the person seeking it.

The person I want to serve is the one tracking low — symptomatic, functional, not yet sick by clinical definition, and trying to make sure they don't become so. They need testing that goes beyond reference ranges. They need interpretation that reads patterns rather than individual values. They need an approach that treats food, sleep, movement, stress, and gut function as clinical variables rather than lifestyle factors. And they need a practitioner who takes their experience seriously rather than telling them their bloods are normal.

That is what this practice is built for. Not to replace medicine. To fill the gap it leaves.