A laboratory reference range describes what is common in the tested population, not what is optimal for you. Several values — ferritin, vitamin D, fasting insulin and triglyceride-to-HDL ratio — carry useful information well before they cross into the flagged range.
What a reference range is, and is not
A reference range is derived from the distribution of results in a reference population. It describes what is common. In a population where deficiency is widespread, common and healthy are not the same thing.
This matters most for ferritin and vitamin D, where a result at the very bottom of the range prints without a flag and is frequently the explanation for the symptom that prompted the test.
Is this what is happening to you?The two-minute check further down asks four questions and shows the result immediately. No email, no call.
Take the 2-minute checkThe eight
Taken together, these cover metabolic, thyroid, iron and liver status.
- HbA1c — three-month average glucose. Above 5.7% is prediabetes territory and worth acting on.
- Fasting insulin — rarely ordered, and the earliest signal of insulin resistance. Ask for it.
- Triglyceride to HDL ratio — divide one by the other. A high ratio suggests insulin resistance even when total cholesterol looks fine.
- Ferritin — iron stores. Haemoglobin falls only after stores are exhausted, so ferritin fails first and explains fatigue and hair fall long before anaemia appears.
- Vitamin D — widely low in India, including in people with substantial sun exposure.
- TSH with free T3 and free T4 — TSH alone can miss a conversion problem.
- ALT and AST — liver enzymes. A mildly raised ALT is commonly the first sign of fatty liver.
- Vitamin B12 — frequently low in vegetarian diets, and it produces fatigue and neurological symptoms.
2-minute check
Why are you so tired?
Four questions. Fatigue nearly always has a findable cause.
How much do you sleep, and how well?
Any hair fall, breathlessness on stairs, or heavy periods?
Do you crash in the afternoon?
Any low mood or difficulty concentrating?
No obvious driver from these answers
If it persists, thyroid, ferritin and vitamin D are the sensible first tests.
There are likely contributors here
Ferritin, thyroid and vitamin D between them explain most persistent fatigue.
Several contributors appear to be present
This is worth testing properly rather than pushing through. All three common causes are treatable.
This check is an indication, not a diagnosis. It does not replace medical advice.
Values that look normal and are not
A ferritin of 15 is inside most reference ranges and is a plausible cause of persistent fatigue and hair fall. A vitamin D of 22 prints without a flag in many laboratories and is insufficient. An HbA1c of 5.9% is not diabetes and it is not nothing.
The pattern across a report is usually more informative than any single flagged value — which is the argument for having someone read the whole thing rather than scanning for red text.
What to do with the report
Take it to your doctor. Nothing here is a substitute for that, and a number read without the clinical context of the person it came from is a poor guide to anything.
What we add is the nutritional layer: what is low, what that explains, what food can realistically correct and what needs medical treatment instead. Those are different questions and they deserve different answers.
In short
Questions we are asked
How often should I have a blood test?
For most adults without a diagnosed condition, a basic metabolic panel every one to two years is reasonable, earlier where there is a family history. Your doctor should set the interval for your circumstances.
My report is all normal but I feel exhausted. What now?
Ask specifically for ferritin, vitamin D, vitamin B12 and free T3, which are often not included in a basic panel. Persistent fatigue with a genuinely complete normal panel still deserves proper investigation.
Reading about it is the easy part.The assessment turns this into your own numbers — free, with a free first consultation, and no figure quoted that we cannot substantiate.
Start my free assessmentConditions this relates to
Recipes that put this into practice
Methi thepla with curd
The same thepla, with a flour blend and a partner that flatten the glucose rise.
See the recipe →Moong dal chilla
Thirteen grams of protein at breakfast, and the difference shows up at four in the afternoon.
See the recipe →Cinnamon and fenugreek water
Two minutes, modest real evidence, and an honest account of its limits.
See the recipe →Related reading
Why weight will not move when your thyroid is underactive
When effort stops producing a result, the problem is often not the effort.
Read →Insulin resistance, explained without the jargon
One mechanism sits underneath PCOS, fatty liver, acne and stubborn weight.
Read →Why your waist matters more than the scale
Where fat sits matters more than how much there is — and BMI misses it entirely.
Read →References
- Indian Council of Medical Research — National Institute of Nutrition reference values.
- World Health Organization — serum ferritin concentrations for assessing iron status.
- [Further references to be completed by the medical review panel.]
This article is general health information, written by a clinical nutritionist and reviewed by a doctor. It is not a diagnosis and it does not replace advice from your own clinician. Never change prescribed medication on the basis of what you read here.