“Your labs are normal.”
Few sentences frustrate patients more—especially when they still feel terrible.
Hi, this is your friendly neighborhood, pesky primary care concierge physician, Dr. Kapur, again.
You wake up tired, struggle through the day, fight brain fog, aches, weight changes, poor sleep, or low mood—yet your blood work comes back stamped: “All normal.” It is easy to walk away thinking, “Is this just in my head?” or “Is this just aging?”
In reality, there is often a gap between “normal” lab results and what is truly optimal for how your body feels and functions day to day. This is the gray zone where many “I don’t feel well, but my doctor says everything is fine” stories live.
What “Normal” Lab Ranges Really Mean
Most lab reference ranges are statistical, not biological. They are usually built so that about 95% of the population falls “in range.” That population includes people who are sedentary, sleep-deprived, inflamed, insulin-resistant, and already living with early chronic disease.
So if your numbers are “normal,” it only means they are similar to the average person—not necessarily that they are ideal for long-term health, energy, mood, and performance.
A better question than “Is it normal?” is:
“Is this value in a range where people tend to feel and function their best, and have lower long-term risk?”
That is the difference between normal and optimal.
The Gap Where Symptoms Live
The gap between normal and optimal is often where the following begin to show up—long before a disease label appears on your chart:
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Fatigue and low resilience to stress
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Brain fog and low motivation
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Weight gain despite doing “everything right”
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Poor sleep and low mood
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“Borderline” blood pressure, sugar, or cholesterol
You can think of it this way:
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“Normal” is the absence of obvious disease on standard tests.
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“Optimal” is the presence of robust metabolic, hormonal, and inflammatory health.
Common Blood Tests: Normal vs. Optimal
Here is how I often think about some key blood tests, with conventional “normal” ranges versus tighter “optimal” targets. Exact ranges vary slightly by lab and clinical situation, and these are general adult, non-pregnant values.
| Test | Normal Range* | Optimal Target* |
|---|---|---|
| HbA1c (%) | < 5.7 | < 5.4 |
| Fasting insulin (uIU/mL) | < 25 | < 5 |
| Homocysteine (µmol/L) | < 15 | < 10 |
| hs-CRP (mg/L) | < 1 | < 1 (the lower the better, above 0) |
| Vitamin D (ng/mL) | > 30 | > 60 |
| Vitamin B12 (pg/mL) | > 220 | > 600 |
| Folate / B9 (ng/mL) | > 3 | > 10 |
| TSH (IU/mL) | 0.4–4.0 | 1–2 |
| Free T3 (pg/mL) | 2.0–4.4 | 3.2–4.2 |
| Free T4 (ng/dL) | 0.82–1.77 | 1.0–1.5 |
| Total cholesterol (mg/dL) | < 200 | Context & particle distribution matter more than total alone |
| HDL – men (mg/dL) | > 40 | > 50 |
| HDL – women (mg/dL) | > 50 | > 60 |
| Triglycerides (mg/dL) | < 150 | < 100 (often 50–80) |
| LDL-C (mg/dL) | < 100 | Often < 100; more aggressive targets depend on risk |
| TG/HDL ratio | < 2 | Around 1 or slightly below |
| ApoB (mg/dL) | < 90 | < 80 (lower for high-risk patients) |
| Lp(a) (mg/dL) | < 50 | < 30 |
| Hemoglobin – men (g/dL) | 13.5–17.5 | > 14 |
| Hemoglobin – women (g/dL) | 12–15.5 | > 13 |
| Ferritin (µg/L) | 12–300 | ~40–90 |
| Total testosterone – men (ng/dL) | 300–1000 | > 600 (age-dependent) |
| Free testosterone (pg/mL) | > 50 | Higher end of normal for age/sex |
| Creatinine (mg/dL) | 0.6–1.3 | Toward the lower end, with strong kidney function and good muscle mass |
| Uric acid (mg/dL) | 3.4–7.2 | < 5.5 |
| Fasting glucose (mg/dL) | 70–99 | ~65–85 (without hypoglycemia) |
| 1–2 hr post-meal glucose (mg/dL) | < 140 | < 120 |
| Post-meal insulin (uIU/mL) | < 40 | < 20 |
| GGT (U/L) | < 50 | < 25 |
| AST (U/L) | 8–48 | < 20 |
| ALT (U/L) | 7–55 | < 20 |
| Serum albumin (g/dL) | 3.5–5.0 | 4.0–5.0 |
| Total bilirubin (mg/dL) | 0.1–1.2 | 0.3–1.0 |
| ALP (U/L) | 40–129 | 30–80 |
| BUN (mg/dL) | 6–20 | ~10–16 |
| Calcium (mg/dL) | 8.7–10.2 | ~9.2–10.0 |
| Sodium (mEq/L) | 135–145 | 137–142 |
| Chloride (mEq/L) | 96–106 | 100–106 |
| Serum iron (µg/dL) | 60–170 | 85–130 |
| TIBC (µg/dL) | 240–450 | 250–350 |
| TSAT (%) | 15–50 | 25–35 |
*These are generalized references and “optimal” targets and will vary by lab, age, sex, and clinical context. They are not rigid treatment thresholds and do not replace individualized medical advice.
Three Quick Examples
1. “Normal” sugar vs. optimal metabolic health
You may be told your fasting glucose of 98 mg/dL and HbA1c of 5.6% are “fine.” You are technically non-diabetic. But if your fasting insulin is 18 and your post-meal insulin is 35, your pancreas is working very hard to keep sugars “normal.” That often shows up as fatigue, weight gain around the middle, brain fog, and afternoon crashes.
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Normal: No diabetes yet.
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Optimal: Low-normal glucose with low-normal insulin and a low triglyceride/HDL ratio—signs of true insulin sensitivity.
2. “Normal” thyroid vs. optimal thyroid
A TSH of 3.8 with “normal” free T4 may be reported as fine. For some people—especially those with symptoms like cold intolerance, constipation, weight gain, hair loss, and brain fog—that may not be where they feel best. Many feel and function better with TSH closer to 1–2 and free T3 in the upper half of the range.
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Normal: Not overt hypothyroidism by strict criteria.
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Optimal: Thyroid values in a tighter range where tissues receive enough hormone to run at full power.
3. “Normal” iron vs. optimal energy
A ferritin of 18 µg/L is technically “in range,” but many people—especially women—feel exhausted, short of breath with exertion, and notice hair thinning at that level. Raising ferritin into the 40–90 range (while monitoring iron saturation and the cause of low iron) often correlates with improved energy, exercise tolerance, and hair quality.
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Normal: Not frankly anemic.
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Optimal: Iron stores robust enough to support oxygen delivery, mitochondrial function, and hair growth.
How to Use This Information Safely
A few important points:
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Lab numbers never exist in a vacuum. Symptoms, exam findings, personal and family history, medications, and imaging all matter.
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“Optimal” is a direction, not a rigid rule. One person’s best ferritin, HbA1c, or TSH will not be identical to another’s.
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More testing and more treatment is not always better. The goal is not to medicalize every minor variation, but to recognize meaningful patterns early.
If your lab report says “everything is normal,” but you still do not feel well, it may be time to ask a different question—not “What disease do I have?” but “How close am I to optimal?”
The Take-Home Message
The gap between normal lab ranges and optimal values is where many “Everything is fine, but I’m not feeling good” problems lie. When we aim not just for the absence of disease but for the presence of optimal metabolic, hormonal, inflammatory, and nutritional status, patients often report:
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Better energy and mood
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Easier weight management
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Sharper thinking and focus
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Better sleep and recovery
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Lower long-term risk of cardiometabolic disease
In my practice, the goal is not perfection on paper, but alignment between how your numbers look, how your body feels, and how you want to live.
Please make an appointment with me in person to discuss this in more detail, and let’s update your blood work if it has not been done recently.
If you are new to KC Primary Care or not yet established as a patient, you can start by scheduling a phone consultation to determine whether this approach is right for you.
Disclaimer: This content is for educational purposes only and does not replace individualized medical advice. Lab interpretation and treatment decisions should always be made in consultation with a qualified healthcare provider.
