Why your GP says your blood tests are normal (and what that actually means)
You got your blood results back. Your GP called to say everything looks fine. So why do you still feel awful?
This is one of the most common things I hear in clinic. And it is not because your GP is wrong, exactly. It is because "normal" and "optimal" are not the same thing.
Pathology reference ranges are built from a population average. They are designed to catch overt disease or deficiency, not to identify the gap between disease and thriving. When your ferritin comes back at 32 and the lab range says anything above 30 is normal, your GP is technically correct. But clinically, a ferritin of 32 can still feel terrible. You may be exhausted, your hair could be falling out, and you are going to struggle to regulate your temperature - none of which will show up as "abnormal" on paper (and may not only be to do with iron status either!)
Here are the results I look at most differently in clinic:
Ferritin. I really want to see women at 50 or above, and above 80 before conception ideally. The difference between 15 and 60 is the difference between functioning and actually feeling well.
TSH. The reference range typically goes up to 4.0 or even 4.5. Most people without thyroid disease have a TSH below 2-2.5. If yours is 3.7 and your GP says it is normal, that is technically true. But functionally, that is the upper end of the range and worth watching, especially if you have symptoms like fatigue, hair loss, cold hands, or difficulty losing weight. We also need more information about T4, T3 and thyroid antibodies before properly making a call.
Vitamin B12. The range usually starts at around 150 pmol/L. I want to see people above 400, ideally closer to 600. Low-normal B12 with symptoms is still low B12.
Fasting insulin. This one is often not even tested, which is a problem. A normal fasting glucose does not rule out insulin resistance. You need fasting insulin alongside glucose to calculate HOMA-IR and actually understand what your metabolism is doing.
This is not about distrusting your GP. It is about understanding that standard pathology is designed for a different purpose than functional medicine. A result can be within range and still be contributing to your symptoms.
If you have ever looked at your results, been told everything is fine, and still felt like something was off - it might be worth having someone read them with a different lens and joining all the dots.
That is exactly what I do in a clinical consultation or through In My Clinical Opinion. If you have recent pathology sitting in a folder somewhere, bring it. A functional medicine read on your results can change everything and finally give you an effective path forward that makes sense for your symptoms and your life.
