Functional Diagnostics –
The Key to Functional Medicine

Mindd Foundation

Functional Medicine Functional Diagnostics

Functional Diagnostics and Testing provides an effective way for practitioners to identify the root cause of disease.  This focus on cause over symptoms, combined with a Functional Medicine treatment approach that views the body as one integrated system, provides a personalized approach for optimal healthcare outcomes.

Identifying the Root Cause of Symptoms

Functional practitioners adopt a holistic and personalized approach, first by taking a very detailed history that includes diet, lifestyle and genetics.  From there they are able to recommend functional tests that may look at blood, urine, stools and/or saliva to better understand the patient.

This new testing context is referred to as Functional Diagnostics and provides a holistic view of a patient’s:

  • genetic predisposition
  • nutritional biochemistry
  • gut and microbiome health
  • environmental toxin burden
  • metabolism
  • lifestyle and dietary factors

Hormone Testing (Adrenal and Reproductive)

When people are stressed, their adrenal glands produce higher than normal levels of the hormone cortisol.

Any stressor, be it sleep disruption, nutritional imbalance, chronic pain or psychological stress will cause cortisol levels to rise.

Reproductive hormones can also have a profound effect on both men’s and women’s health. Imbalances in these hormones cause fatigue, sleep and mood disturbance, loss of libido, loss of muscle mass and weight gain. In women, estrogen and progesterone imbalances can cause PMS and menopausal symptoms, and in men, low testosterone can cause lack of libido, hair loss, and weight gain.

Research shows that most chronic illness involves some adrenal gland dysfunction, so this test is a cornerstone of Functional Diagnostics.

Food Sensitivity and Gluten Intolerance

Many people have food sensitivities without even realizing it. Often gluten, dairy, and egg sensitivities are an underlying reason for a range of symptoms.

There are also lesser-known sensitivities to foods such as garlic, bananas, and cranberries.  And if the patient has had leaky gut, that patient could very well be sensitive to many foods whose particles have leaked through the digestive tract into the blood.

To test for these issues, functional medicine practitioners perform a test called an Elimination and Challenge test.  For 21 days, the patient eats a very restricted diet, removing all possible stressors like eggs, nuts, shellfish, dairy, citrus, soy, gluten and more. After the 21 days, the practitioner reintroduces each food one by one to determine any food sensitivity.

There is also a finger-stick test that tests about 100 foods—in a much shorter amount of time.  This test is not looking for full food allergies but for more subtle reactions and symptoms that can often be delayed for 72 hours after eating the food.

Gluten intolerance is well recognized and affects millions of people. For most people, gluten intolerance is not severe however it can produce symptoms including arthritis, skin rashes, fatigue and brain fog.  In functional medicine, there are also saliva and stool tests to look for gluten intolerance.

Gut Microbiome Tests

Gut health and overall health are inextricably linked.

Good health starts in the gut with the gut microbiome, millions of microbes that live in the human intestinal tract including bacteria, fungi, protozoa and non-living virus.

Emerging research indicates that people worldwide are struggling with digestive dysfunction from a damaged gut microbiome driven by toxins, pesticides, processed foods and medications such as antibiotics.  A damaged microbiome leads to various health complications like inflammation and infection.

In functional medicine, the microbiome can be tested and an experienced practitioner can work to restore gut health through diet, nutrient therapy, herbal medicine and lifestyle measure.

Metabolic Testing

Metabolism refers to all chemical reactions involved in maintaining the living state of cells Metabolic imbalances can cause mood swings, fatigue, weight gain, gastrointestinal issues and hormone imbalances to name a few.

Metabolic testing gives insight into hundreds of processes that support everything from producing energy to detoxification.  It also helps determine nutritional status.

Heavy Metal Testing

Toxic heavy metals like lead, aluminum, mercury and other toxins like PCBs and pesticides are increasingly present in our food, medications and environment and can wreak havoc on all body systems including the central nervous system which when damaged can adversely affect focus, memory, and concentration.

Many diseases today, Parkinson’s, Alzheimer’s and multiple sclerosis (MS) are diseases of the central nervous system. Functional medicine doctors aim to release these toxins from the body to improve overall health.

Lyme Disease

Lyme disease is the fastest-growing infectious disease in the U.S. and is rapidly spreading across the world. Lyme disease is often misdiagnosed as MS, arthritis, chronic fatigue syndrome, fibromyalgia and Parkinson’s, to name a few.

Research has also discovered a link between autism and Lyme disease which may have to do with the gut and dysregulation of the immune system.

Testing for Lyme disease is challenging. However functional medicine doctors recommend the IgG and IgM Western Blot Tests as a starting point.

Functional Diagnostics to Improve Patient Health

Functional Diagnostics The goal is to be proactive and preemptive to prevent symptoms from becoming more severe conditions in the future as well as being able to treat current illness effectively.


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  1. Institute of Functional Medicine.
  2. Bland J. Defining Function in the Functional Medicine ModelIntegr Med (Encinitas). 2017 Feb; 16(1): 22–25.
  3. Hyman, M. Functional Medicine Testing: Redefining Disease. May 2010.


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