What is Functional Lab Testing?

There are two main types of ranges in the field of blood chemistry analysis: a pathological range, and a functional range. Most conventional health models only look for the pathological range and don’t assist patients in working towards the ideal functional range.

The pathological range is used to diagnose disease; the functional range is used to assess your risk for disease, before the disease develops. The references that are provided with laboratory test results are referred to as “the pathological range,” because if the test results are out of range, it usually indicates potential for pathology or disease.

The main difference between the functional range, and the pathological range, is the degree of deviation allowed within their normal range. For example the functional range for glucose may be 3.7 – 5.6 mmol/L, but the pathological range may be 6.0-11.0 mmol/L

Levels above the pathological range may indicate diabetes. Levels above the functional range, before they reach the extremes of the pathological range, may indicate insulin resistance and future risk for developing diabetes.

The pathological lab values provided on the lab results are actually based on a “bell curve analysis” of all the people that have been to the lab over “x” amount of time.

If you go to the same lab in two different cities, you will find that the reference ranges are actually different. It is important to look at functional ranges, so you are not considered “normal” or “healthy” because your lab tests fall in the same range as the majority of the sick people that have been to that lab. The sicker the population gets, the wider, and less useful the lab reference ranges become.

The same is true with thyroid conditions. The thyroid is a very important organ of metabolism so it’s function has a huge impact on how we feel. But when you don’t have all the data about how it’s functioning, you’ll often be told that you’re fine when in fact you’ve got all the signs of a thyroid condition and failing to correct it will eventually result in you becoming a lifelong patient - often finding yourself on medication for life.

And that’s because most conventional medical doctors are limited in the number of bio markers they can order to assess thyroid function - often only order TSH (Thyroid Stimulating Hormone) which is only a small part of the thyroid story.

Blood tests for thyroid function should include all of the following—TSH, total T4, free T3, reverse T3, TBG, TSI, and the presence of antibodies—these are all important for understanding how well our thyroid is working.

Without fully evaluating total thyroid function, it’s easy to assume “nothing is wrong with your thyroid” while you still may be experience many thyroid related symptoms such as fatigue, weight loss or gain, hair thinning and brittle nails.

One of the great discoveries of modern medicine is that humans are inhabited by trillions of bacteria, viruses, parasites, and fungi. And not just in the gut, as once believed, but in tissues throughout the body. You are not one, but many—and in an optimal state of health, you coexist in harmony with your microbes.

The largest and most complex microbiome is that of our GI tract, which is estimated to contain as many as 1,000 microbial cells in every gram of stool. Although conventional stool testing looks at a limited number of markers and pathogens, Microbiome mapping fully analyses your gut flora, as well as to look for multiple markers of inflammation or poor digestion which may also contribute to a whole myriad of issues from skin conditions, dysregulation of thyroid or sex hormones, and mood disorders.

Functional Microbiome mapping stool tests look at many biomarkers far beyond the standard stool test, including:

• Digestion and absorption levels
• Inflammation levels
• Presence of a large variety of species - parasites, yeast overgrowth and worms
• A full gut microbiome breakdown
• Bacteria including h. Pylori, Campylobacter, Clostridium difficile

Often Confused: IgE And IgG Food Allergies

Many times when a person suspects a food sensitivity they are sent for food allergy (IgE type 1) testing. When those tests are found to be negative people are often told everything is fine even when they sense  that something is wrong.

Difference between classic IgE food allergies and delayed IgG food allergies

There are various reasons why a food can cause problems, among them a classic IgE food allergy (type I) and a delayed IgG food allergy (type III), the latter is also referred to as food intolerance. What both allergies have in common is that the immune system is involved. However, there are some differences in the way it responses.

Classic IgE food allergy

A classic type I allergy is when the immune system produces specific IgE antibodies (immune globulins of the subclass E). These antibodies lead to an immediate allergic reaction. The symptoms appear within seconds or minutes: severe swelling, breathing difficulty, rash, itching skin or even anaphylactic shock.

Someone who has a type I allergy will most probably know which food is causing problems, because the symptoms appear right away. Therefore, blood testing is not necessarily needed to identify this kind of allergy. IgE tests are mainly performed for confirmation. 

Delayed IgG food sensitivity

A type III food sensitivity is when the immune system produces specific IgG antibodies (immune globulins of the subclass G). These antibodies can lead to inflammatory processes. The symptoms appear up to three days after the consumption of a trigger food. Learn more.

It is very difficult to pinpoint which food causes you problems because of the delayed appearance. An IgG test helps to localise and limit the suspects.