Why Your Lab Results Are “Normal” But You Still Don’t Feel Well

Have you ever been to the doctor and been told, “All your blood tests look normal, keep doing what you’re doing.”?   What they really mean is “Keep doing what you’re doing until your labs come back abnormal (i.e., out of range).  Then, we can help you.” 

You see, doctors are trained to look for disease when it reaches the clinical state (i.e., lab results are out of range). A lab’s reference range is considered by the medical profession to be the “normal range”.  But “normal” doesn’t reflect what is healthy; it reflects what is common among the population.

Normal ranges are designed to identify and diagnose disease states. So, when a doctor reviews a patient's blood test results, their primary concern is whether a particular result is outside the normal lab value range.  The problem is that the normal reference ranges represent average populations, rather than the optimal level required to maintain good health. 

Most normal reference ranges are far too broad to adequately detect health problems before they become pathology (i.e., a disease state), and are not useful for detecting dysfunction early.  This can explain why you don't feel well, but your lab ranges are all “normal”.

The conventional standard or “normal” reference ranges you see on your lab results are based on a Gaussian distribution of a bell curve. This means that if you take a group of people such as 1,000 or 20,000 or 100,000 people and test them, you're going to get a wide spectrum of blood results.  And typically, they will fall underneath a bell curve.  The further out, high or low, the less people are going to fall within the bell curve.

The Gaussian distribution of a bell curve says that 95% of the population are going to be considered “normal”. That is, 2.5% of the population are above normal and 2.5% are below the normal range.  This is based purely on statistics and not whether a certain value represents good health or function.

The other problem is that normal reference values change.  They can change from year to year depending on the prevalence of disease in the general population or new scientific research deems it necessary.  You may have seen a notation on your lab results at some point indicating a change in the lab’s reference ranges.  Labs will also put out a statement highlighting a change in a certain lab marker¹. 

This process compounds the issue because, as the population continues to get sicker, lab ranges are modified to the average, making it even more challenging to identify dysfunction early. 

It’s no surprise that improvements to your health can be made more readily with early detection.  Identifying what blood markers are not optimal from a Functional Nutrition perspective is key to this.

I’m going to use the homocysteine reference range as an example.  Homocysteine is a non-essential amino acid created by the body as a by-product of a critical conversion process called methylation.  As with so many other substances in the body, homocysteine can build up if our methylation process is impaired or blocked (this can happen, for instance, if you have the MTHFR , MTR and/or MTRR gene mutations).

Homocysteine is one of the important blood markers I suggest everyone have tested because it’s associated with cardiovascular and neurological health, among other things.

Until recently, it was considered “normal” to have a homocysteine blood reading as high as 15 μmol/L.   So, for many years the normal reference range for homocysteine said, for instance, if you're 14.8 μmol/L, that's considered to be normal and there's no problem. This level has since been changed by most labs to being in the “normal” range if your results are less than 10.4μmol/L.

The optimal level of homocysteine, however, based on scientific research used in the Functional Nutrition framework^2-8, is between 6-7 μmol/L.  When your level is above 7, there is a higher risk of heart attack, stroke, Alzheimer’s Disease, among other conditions. 

There are also risks if your homocysteine is too low (i.e., less than 6 μmol/L).  Risks include elevated oxidative stress because low homocysteine limits the body’s capacity to deal with certain kinds of toxins and can cause the overproduction of ammonia, hydrogen sulfide, and potentially neurotoxic sulfites.

These are such significant differences.  By identifying whether your homocysteine is in the optimal range (as opposed to waiting until it's out of range from the average population), a little investigative work into what is causing the variation and possibly making some dietary changes and targeted supplementation to keep your level within the optimal range can help you avoid serious health conditions.

Blood testing gives a snapshot of where you are on the continuum from optimal health to full-blown disease.  It can be a useful tool that allows us to gain a lot of insight into the body IF you know how to interpret the results from a functional perspective.  That is, using the Optimal Range within the Functional Nutrition framework as opposed to the lab range.  The Optimal Range is based on values seen in disease-free populations and, in research studies, have not been associated with an increased risk of dysfunction or disease.

Correlated with your health history, this is how you start to identify issues before they become a problem.  By catching dysfunction early, a plan tailored specifically to your unique needs will help to correct it so that normal function can be restored. 

If you would like to learn more about how I can help you better analyze your blood work results within the Functional Nutrition framework, click here for a free twenty-minute consultation.

Cited References:

1. LabCorp Statement on changes to Testosterone reference range levels among males: https://www.labcorp.com/assets/11476
2. Faeh D, Chiolero A, Paccaud F. Homocysteine as a risk factor for cardiovascular disease: should we (still) worry about?. Swiss Med Wkly. 2006;136(47-48):745‐756.
3. de Ruijter W, Westendorp RG, Assendelft WJ, et al. Use of Framingham risk score and new biomarkers to predict cardiovascular mortality in older people: population based observational cohort study. BMJ. 2009;338:a3083. Published 2009 Jan 8. doi:10.1136/bmj.a3083
4. Boldyrev A, Bryushkova E, Mashkina A, Vladychenskaya E. Why is homocysteine toxic for the nervous and immune systems?. Curr Aging Sci. 2013;6(1):29‐36. doi:10.2174/18746098112059990007
5. Škovierová H, Mahmood S, Blahovcová E, Hatok J, Lehotský J, Murín R. Effect of homocysteine on survival of human glial cells. Physiol Res. 2015;64(5):747‐754. doi:10.33549/physiolres.932897
6. Seshadri S, Beiser A, Selhub J, et al. Plasma homocysteine as a risk factor for dementia and Alzheimer's disease. N Engl J Med. 2002;346(7):476‐483. doi:10.1056/NEJMoa011613
7. Aishwarya S, Rajendiren S, Kattimani S, Dhiman P, Haritha S, Ananthanarayanan PH. Homocysteine and serotonin: association with postpartum depression. Asian J Psychiatr. 2013;6(6):473‐477. doi:10.1016/j.ajp.2013.05.007
8. de Ruijter W, Westendorp RG, Assendelft WJ, et al. Use of Framingham risk score and new biomarkers to predict cardiovascular mortality in older people: population based observational cohort study. BMJ. 2009;338:a3083. Published 2009 Jan 8. doi:10.1136/bmj.a3083