What is Hypothyroidism?

May 10, 2019

When I was diagnosed with Hashimoto’s Thyroiditis, I was struggling with chronic exhaustion, poor memory, brain fog, hair loss, anxiety, irritability, and lethargy. I tried many therapies to try to get my immune system back to balance. I took various supplements and herbal remedies that really helped to reduce my symptoms, but my antibodies always remained high. It wasn’t until I addressed my emotional and mental wellbeing, and began making changes to support my mental health, that my antibodies dropped 1000 units!


I believe that understanding what is happening in your body encourages you to take the right steps in healing yourself, so this article is meant to explain what the thyroid is, how it functions and what causes it to fall out of balance.

The thyroid gland is shaped like a butterfly with its wings spread open wrapped around the front of our trachea at the base of our neck. The thyroid produces thyroid hormones, mainly thyroxine (T4) and triiodothyronine (T3), which enter nearly every single cell in our bodies! This is the reason why there is such a wide range of symptoms associated with thyroid dysfunction. The main functions of these hormones are to control the metabolic rate of our cells and ensure optimal energy production, cell growth and tissue differentiation.

How Does the Thyroid Gland Produce Thyroid Hormones?

Now, lets get to the details of how the thyroid gland works. It all starts at the hypothalamus – the master regulator in the brain that controls our neuroendocrine system. When there isn’t enough thyroid hormone in our cells, there is a warning signal that tells the hypothalamus to produce Thyroid Releasing Hormone (TRH), which in turn tells the pituitary gland (just next door to the hypothalamus in the brain) to produce Thyroid Stimulating Hormone (TSH) – side note: TSH levels are commonly used to test for hypothyroidism. TSH will then travel to the thyroid gland and tell it to produce more thyroid hormones (T4 & T3). The thyroid itself mainly produces T4 (about 80%) and relies on other body tissues (most commonly the liver) to convert T4 into T3. T4 is considered inactive, it needs to be converted into T3 in order to be used by our cells – side note: many people do not feel better on Synthroid (levothyroxine), because they are not converting the medication (which is a synthetic T4 hormone) into T3 properly.

What Causes Hypothyroidism?

So now that we know how the thyroid gland works, we can now investigate how this system falls out of balance. There are a few areas along the pathway mentioned above where things can go wrong.

  1. Hormone Production. Our bodies need certain nutrients in order to make hormones. When we don’t have these required nutrients, the body cannot produce hormones efficiently. The thyroid gland needs iodine, tyrosine, selenium and Vitamin B2 in order to make thyroid hormones, and when we don’t have enough of these nutrients, the thyroid will not produce thyroid hormones efficiently.

  2. Enzyme Function. Our bodies need enzymes in order to activate certain hormones. All enzymes require certain nutrients, called coenzymes and cofactors, in order to do their jobs. The enzyme responsible for converting T4 into T3 is called 5′-deiodinase, and it needs selenium, zinc and B vitamins in order to function properly. A deficiency in these nutrients can impair out ability to convert our thyroid hormones into their active form.

  3. Stress. When we are under stress, our adrenal glands produce a hormone called cortisol. This is our “fight or flight” hormone that helps us get out of sticky situations. However, when we are constantly under stress with work duties, family responsibilities, bills to pay, etc, there is a constant release of cortisol. Cortisol inhibits TSH secretion from the pituitary gland and suppresses 5′-deiodinase function, reducing the production of thyroid hormones and impairing our ability to convert T4 into the active T3.

  4. Toxicity. Since the majority of thyroid hormone conversion from T4 into T3 happens in the liver, it is very important to make sure that your liver is functioning at its best. With increased exposure to toxins from cosmetics, processed food, plastics, pesticides, and chemical solvents, the liver can become overworked and may not able to support optimal thyroid conversion.

  5. Pregnancy. The need for thyroid hormone increases during pregnancy to ensure that the growing baby is receiving enough thyroid hormone to grow and develop properly. This puts a lot of pressure on the thyroid gland and can cause hypothyroidism in the mother before and after delivery.

  6. Autoimmune Process. The most common cause of hypothyroidism is from an autoimmune condition called Hashimoto’s Thyroiditis, in which the immune system attacks the thyroid gland and reduces thyroid function. It is important to check your thyroid antibodies (called anti-TPO) to investigate if this is the cause for you.

How Do I Know if I Have Hypothyroidism?

The first step in investigating whether you have hypothyroidism is by looking at the symptoms. Below is a list of the most common symptoms associated with hypothyroidism

  • Fatigue, lethargy or exhaustion

  • Poor focus and memory impairment

  • Intolerance to cold

  • Mood imbalance – depression or lack of motivation

  • Menstrual irregularities

  • Hair loss

  • Weight gain

  • Constipation

  • Throat pain or pressure

  • Joint pain or muscle aches

The second step is to get lab work done. Most medical doctors only run TSH levels, but this is missing a large piece of the puzzle! It is imperative that you get the following lab work done in order to assess your thyroid function completely:

  • TSH (Thyroid Stimulating Hormone): If these levels are elevated, it is indicative of hypothyroidism. However, these levels can be normal in cases of subclinical hypothyroidism and early stages of hypothyroidism so it is best not to rely solely on this value.

  • free T4 (thyroxine): This value is typically low or low-normal in hypothyroidism.

  • free T3 (triiodothyronine): This value is typically low or low-normal in hypothyroidism.

  • rT3 (reverse T3): This value is typically elevated in hypothyroidism.

  • Anti-TPO: This value is elevated in Hashimoto’s Thyroiditis.

  • Specialized Lab Testing: I offer specialized lab testing in my practice to assess your levels of iodine, selenium and bromine to rule out any deficiencies that may be causing hypothyroidism.

Yours in Health,

Dr. Fiona