THE HERMIT WOLF
TRUTH LOGS
THE HERMIT WOLF
TRUTH LOGS
Modern medicine speaks in numbers. Blood pressure, cholesterol, blood sugar, protein, and many other measures arrive on a lab report with a range beside them. If a value sits outside that range, a letter H or L appears. To the person reading the report, that mark can feel like a verdict: something is wrong.
The question that started this inquiry is simple. Who decided where “normal” ends and “abnormal” begins? The question is not an attack on doctors or on science. Clinics need cutoffs in order to act. Public health needs standards. Patients need some way to know when a result deserves attention. The trouble starts when those cutoffs are treated as if they were laws of nature rather than human decisions about risk.
A fasting blood sugar of 99 is not a different kind of body from a fasting blood sugar of 100. LDL cholesterol does not change its chemistry when it crosses from 99 to 100. Blood pressure does not become a new physiological event at 130 rather than 129. Nature moves in shades. Our reports move in boxes.
Once a box is drawn, it can gain more authority than the evidence behind it. A useful statistical line can start to look like a cliff. After that, the number is no longer only a tool. It becomes a label.
Different organizations sometimes draw those lines in different places. In the United States, the American Diabetes Association has long treated a fasting glucose below 100 as normal, 100 to 125 as prediabetes, and 126 or higher as diabetes. The World Health Organization kept a higher line of 110 for impaired fasting glucose. Similar disagreements exist around the use of HbA1c to define prediabetes.
Move the line down, and millions more people are called abnormal. Move it up, and millions fewer are. Their bodies have not changed. Only the classification has.
That change is not harmless wordplay. A label such as “prediabetes” can affect later tests, medicines, insurance codes, diet advice, and anxiety. Research also shows that many people who meet a broad prediabetes definition do not go on to diabetes, and some return to a normal range without treatment. Blood sugar matters. A cutoff and a biological event are still not the same thing.
A laboratory reference range usually describes how a value is distributed in a selected group of people. A treatment target is different. It is a level doctors may try to reach because studies suggest that doing so improves outcomes. Those two numbers can look alike on a printout. They do not mean the same thing.
A person can sit outside a reference range and not have a disease. Another can sit inside the range and still have a serious problem. To the patient, both may look like one message: this number is good, that number is bad.
LDL cholesterol is a useful marker, and lowering it can reduce heart attacks and strokes in the right people. The harder question is whether one LDL number should be a universal destination for everyone. Some researchers argue that other markers — such as ApoB, particle number, non-HDL cholesterol, or Lp(a) — give a fuller picture of risk. The point is not that LDL is meaningless. The point is that a marker is not the same as the outcome we care about: heart attack, stroke, kidney failure, disability, independence, and survival.
HDL cholesterol is a warning from history. For years it was called “good cholesterol,” and higher seemed better. Later work showed that very high HDL is not endlessly protective, and drugs that raised HDL did not reliably prevent heart events. An attractive story was tested. Biology was more complicated. That is science working, not science failing.
Blood pressure adds another difficulty: the number depends on how it is taken. The SPRINT trial found that intensive treatment reduced events in selected high-risk adults without diabetes or prior stroke, but with more side effects. Its target near 120 was reached with a highly standardized machine protocol. That number should not be treated as identical to a single hurried reading in an ordinary office. Was the person sitting quietly? Was the cuff the right size? Had she just walked in from the parking lot? Was she talking, in pain, or being watched while the cuff inflated? Change the method, and the meaning of the number can change.
In older adults the problem grows. Aggressive lowering can prevent a stroke years from now and still cause dizziness, falls, or a diastolic pressure that is too low tomorrow. The best target for a healthy 40-year-old is not automatically the best target for an 80-year-old with stiff arteries, several medicines, weaker kidneys, or a high risk of falling.
There is a deeper reason these numbers collide. The body is not a row of separate rooms. It is one environment. Organs influence one another because they are parts of a whole. Specialties exist for the convenience of training, research, and billing. Physiology never signed that contract.
Take blood pressure again — not as a clinic target, but as a signal that travels. Change arterial pressure and you change the stretch on sensors in the neck and the aorta. Those sensors alter the release of renin from the kidney. Renin starts a cascade that produces angiotensin and then aldosterone from the adrenal cortex. Aldosterone changes how the kidney holds salt and water. That changes circulating volume, the work the heart must do, and the filtration rate of the glomerulus. The adrenal gland, the nephron, and the myocardium do not hold a meeting. They answer one another in minutes. A guideline that treats “blood pressure,” “kidney protection,” and “heart risk” as three separate assignments is describing the hospital directory, not the organism.
The same fiction appears when a person tries to get care for pain. Years ago I went to an orthopedic doctor with pain in the hip. He would not take the case. He specialized in the hip, he said, and my pain came from the lumbar vertebrae. But the complaint I brought him was hip pain. The femur, the pelvis, and the lower spine share nerve roots, fascia, and the act of walking. A physician who will only see a worn hip socket is not being precise. He is refusing the anatomy that produces the symptom.
Something similar happened with carpal tunnel. The doctor could not see me because he specialized in the wrist, and in his view the syndrome I brought him had nothing to do with the wrist he studied. The median nerve is compressed in a tunnel at the wrist, but the hand is not a closed room. The neck, the brachial plexus, the forearm, swelling from other illnesses, and the way a person uses the hand all belong to the same pathway. If the doctor who “does wrists” cannot see a problem that lives in the wrist, the specialty has become a wall, not a lens.
We keep dividing the body and its ailments. They remain a single environment, each part influencing the rest.
That is why a practical collision in daily life is not a side issue. It is the same fact seen from the kitchen table. A person with diabetes may need to limit carbohydrate in order to keep glucose under control and reduce insulin demand. Calories do not vanish when carbohydrate is removed. They usually have to come from fat, protein, or both.
Raise fat, and cholesterol and heart risk enter the conversation. Raise protein, and kidney function enters it — especially if the kidneys are already impaired. Eat too little protein, especially in later life, and muscle wasting becomes the danger. Food intolerances then close still more doors. Each rule can make sense by itself. The difficulty appears when all of them must share one meal and one organism.
Medicine divides the body into specialties because no one can master every field. The patient does not arrive divided. The pancreas does not know which guideline belongs to endocrinology. The kidney does not stop talking to diet because the plan was written for diabetes. Muscle, insulin, lipids, appetite, age, and quality of life occupy the same person.
So the useful question is no longer only, “What should this laboratory value be?” It becomes: what combination of choices produces the best overall result for this particular person, and what compromises are justified when improving one number makes another harder to live with?
Advice on saturated fat and protein is often given as if a single percentage or gram count were a law. The evidence is more tangled. The source of the fat, and what replaces it, may matter as much as the percentage. The familiar adult protein figure of 0.8 grams per kilogram per day is closer to a minimum to avoid deficiency than to an ideal for every adult. Older people, active people, and people trying to keep muscle may need more. A population minimum and a personal optimum are not the same idea.
Guidelines are not the enemy. Without them, care would be more uneven and more open to individual bias. They gather large amounts of evidence and help doctors act. The danger is forgetting what a guideline is: a structured reading of the evidence at a moment in time. It can be revised. Different groups can disagree. Targets depend on which outcomes were prized, how measurements were made, who was studied, and how a committee weighed benefit against harm.
The red H on a lab slip does not know the patient’s age, medicines, symptoms, fasting state, hydration, how the sample was taken, or whether the change is new or old. It does not know whether treating that number will improve a life. It is a flag, not an interpretation.
Better questions follow from that fact. What event are we trying to prevent? How much does my own risk change if this number changes? Is this a lab range, a diagnosis line, or a treatment goal? How strong is the evidence in people my age? Was the reported benefit a large relative change or a small absolute one? What harms appeared in the treated group? Did the study measure blood pressure, sugar, or cholesterol the way mine was measured? Are there competing risks? Would changing this number improve something that actually matters to me?
Those are not hostile questions. They are the questions evidence-based medicine requires.
The human body did not evolve with knowledge of LDL cutoffs, HbA1c categories, or blood-pressure stages. We invented those boxes because they help us organize risk and make decisions. They are useful, often indispensable.
A biomarker is evidence. A threshold is a decision boundary. A guideline is an interpretation. A specialty is a way of studying one part of a whole that was never separate. Medicine at its best is the careful work of deciding what all of these mean for the particular human being sitting in the chair.
