A recent study indicated that nearly 13 million Americans may be undiagnosed for low thyroid function. This is in addition to the approximately 20 million individuals who are receiving thyroid replacement treatment for hypothyroidism. Why the large discrepancy in diagnosis? One reason may be inadequate testing for thyroid hormone levels, and the sole reliance by medical practitioners on these lab tests despite the individual's specific health complaints. Just as important is that these numbers may are too high from the sole reason that too many people are diagnosed with a primary thyroid disorder, when the real reason for their low thyroid symptoms is due to adrenal gland exhaustion.

The thyroid receives information from the pituitary gland in the form of TSH (thyrotrophin stimulating hormone). This hormone under direct control from the brain directs the thyroid to produce thyroid hormone. Thyroxine (T4), which is relatively inert and tri-iodothyronine (T3), the biologically active hormone are made in an approximately 90/10 ratio. This preserves a steady pool of T4 for conversion to T3 which is needed for cellular energy.

Once T3 is our cells it activates enzyme pathways that increase energy production, protein synthesis, fat and carbohydrate breakdown, increased tissue oxygenation and mineral utilization. Thyroid hormone activates over 100 enzymes to produce a multitude of bodily functions. In fact, the brain, heart, lungs, intestines, sex glands and muscles owe much of their function to normal thyroid physiology. As will be discussed, the thyroid gland is also greatly influenced by adrenal hormone balance.

Are You Hypothyroid (and/or Low Adrenal)? - Signs and Symptoms
The symptoms of low thyroid are extensive and touch on many aspects of our physical and mental/emotional well-being. It is important to realize that thyroid hormones regulate energy production. Therefore, hormone production and balance, immune function, digestion, biochemical regulation, thought and mood production can all be effected. However, this list is not exclusive to low thyroid, as adrenal gland dysfunction can lead to many similar physical complaints:

• Depression and Anxiety
  
• Insomnia and Restlessness
  
• Fatigue and Weakness
  
• Heart Problems
  
• Decreased Libido and Sex Hormone Issues
  
• Weight Problems
  
• Blood Sugar Imbalances
  
• Cold Sensitivity, Dry Skin and Brittle Nails
  
• Infertility and Miscarriages
  
• Retarded Growth in Children
  
• Cholesterol Problems
  
• Immune Dysfunction
  
• Osteoporosis
  

Thyroid Testing - The Area of 'Repeated' Misdiagnosis
A recent report in the Journal of the American Academy of Endocrinology revealed that the range for TSH may be too broad. That is, numbers approaching the upper range of normal, ie. 4.25 to 5.0 may in fact be developing hypothyroidism. Our experience is that TSH numbers above 2.0 (sometimes 1.5) indicate a potential underactivity of thyroid function.

Free T4 and Free T3
These two measurements, along with a highly sensitive TSH are necessary to adequately evaluate thyroid hormone production (the normal range for FT4 is .70 - 1.53 and FT3 is 2.3 - 4.2.) along with an adrenal stress hormone profile from BioHealth Diagnostics. Anything less is inadequate. However, it is still important to look at these numbers in the context of the patient's history. Many other factors such as elevated cortisol levels and environmental factors can impact on thyroid function.

T4 to T3 - Factors Controlling Conversion
The conversion of T4 to T3 is a crucial step in the process of thyroid function. If this step is deficient or altered in any way the individual will suffer with symptoms of low thyroid.

• Starvation, diabetes, uremia, and other chronic debilitating conditions and diseases
• Nutrient deficiencies, most notably selenium
• Zinc, glutathione, cobalt, vitamin D and riboflavin deficiencies have been implicated
• High carbohydrate diets
• Stress
• Increased cortisol response

Other Factors of Thyroid Inhibition
Besides the effects on T4 to T3, there are many other factors that inhibit thyroid function:

• Chemical exposure from PCB's, PVC's, DNP's, Red Dye #3, cigarette smoke, and halogenated organic compounds
• Chlorine and flouride.
• Heavy Metal exposure such as mercury from fish, water, vaccines, and dental filling contamination.
• Certain flavonoids in foods such brussel sprouts, rutabaga, turnips, cabbage, radishes, cauliflower, and soy products. Millet has the highest content of antithyroid flavonoids.
• Radiation exposure
• Neck Trauma/Whiplash
• Basal Body Temperatures (BBT) - Factors Beyond the Thyroid

In the early 1980's Broda Barnes, M.D. wrote a book titled "Hypothyroidism: The Unsuspected Illness." Dr. Barnes advocated the use of axillary (armpit) basal body temperature as an indication of hypothyroidism. The premise is simple: If your 5 day average basal body temperature is below 97.6 then you are suffering with low thyroid function. The basal body temperature reading is a good way to assess low functioning metabolism, it does not allows indicate a primary thyroid problem. Other factors can impact body temperature leading to false diagnosis of hypothyroidism.

Cortisol and the BBT Riddle
When our bodies are confronted with stress, the adrenal glands are stimulated to secrete cortisol which is necessary to meet the demands for increase fuel and energy by our muscles and brain cells. In a normal situation, the cortisol levels drop after the stressful event to their normal levels. However, for many people elevated cortisol levels become the norm leading to a multitude of problems including low thyroid function via the inhibition of TSH and the conversion of T4 to T3. In relationship to body temperature cortisol is a key factor in setting the core temperature set point. With chronically elevated cortisol levels, especially in the morning the basal body temperature will be low.

It is important to realize that basal body temperatures are a good way to assess problems with the metabolic state of the body including thyroid function, but can give a false analysis of primary low thyroid function leading to unnecessary thyroid treatment.

I generally recommend an individual perform an adrenal hormone profile, and begin to address lifestyle and dietary factors that may be stressing adrenal gland function before embarking on the path of thyroid hormone and supplement replacement.