Do you constantly feel tired, possibly even depressed? Are you experiencing hair loss or weight gain. You’ve most likely heard that these are symptoms of hypothyroidism and have maybe even gone to your doctor to have your thyroid assessed. But what do you do when the labs come back “normal” or you’re put on medication but the symptoms don’t go away?

You are not alone in feeling like your thyroid isn’t functioning optimally but being told that everything is fine. The good news is, if you dig a little deeper, your intuition could be proven correct as hypothyroidism is vastly underdiagnosed. In fact, it is estimated that about half of people with hypothyroidism aren’t even aware that they have it!

What is the Thyroid Gland?

The thyroid gland is a butterfly shaped gland that is found in your neck. It is responsible for regulating the metabolism and energy for your entire body via the production of two hormones, triiodothyronine (T3) and thyroxine (T4).

The Thyroid Hormones


Thyroid Stimulating Hormone (TSH) is a hormone that is secreted from the pituitary gland in the brain. It’s sole function is to tell the thyroid gland to secrete its hormones, T3 and T4. When the levels of the active hormones (T3 & T4) drop, or the gland stops responding adequately, TSH levels go up as the body tries harder to stimulate the thyroid. This is why hypothyroidism is characterized by high levels of TSH.


Thyroxine is the most abundant hormone that is produced by the thyroid gland. T4 is made from the amino acid tyrosine combined with 4 atoms of iodine. Selenium and zinc are also used during the chemical reaction. Deficiencies in any of these four nutrients will lower the output of T4 and impair thyroid function.


The problem with T4 is that it is a very weak hormone and cannot be used by the body very well. Due to this, the majority of T4 is converted into the hormone T3 in various organs of the body. T3 is the active thyroid hormone and is needed in sufficient amounts for the body to carry out its processes. Having low levels of T3 will result in symptoms of hypothyroidism.

Reverse T3

Reverse T3, an inactive form of T3, is naturally made in small amounts by the body from T4. However, when the body needs to conserve energy such as in times of illness, famine, or chronic stress, the body will start converting more and more of the available T4 into reverse T3. This causes T3 (our active hormone) levels to plummet. Not only will T3 levels start to fall, but the reverse T3 will bind to cell receptors and prevent the little T3 you do have from carrying out it’s job.

What is Hypothyroidism?

An underfunctioning thyroid gland is referred to as hypothyroidism. This condition is especially prevalent in women, especially in the months after childbirth or after menopause. It is thought to affect as many as 10% of women, many of whom do not even realize they have it!

As the thyroid gland is the metabolic centre for the entire body, it is no surprise that the symptoms of hypothyroidism are diverse and present in every area of the body. The most common symptoms that I see in my practice are fatigue, unexplained weight gain, hair loss or dry hair, increased sensitivity to the cold or feeling generally cold, and constipation. However, low thyroid function can also result in symptoms of depression or low mood, anxiety, dry skin, trouble concentrating, and impaired memory or “brain fog”. Further, pain or stiffness in your muscles or joints, muscle weakness, generalized swelling, and cavings for carbs or sugar are also symptoms of hypothyroidism.

Hypothyroidism also greatly affects the female reproductive system. Symptoms from irregular periods to very heavy flow can sometimes be attributed to poor thyroid function. Similarly, if you’ve been experiencing repeated miscarriages, or infertility, you may want to have your thyroid checked!

Symptom Checklist

  •  Fatigue
  • Unexplained weight gain
  • Increased sensitivity to the cold
  • Constipation
  • Dry skin
  • Hair loss or dry hair
  • Muscle weakness
  • Muscle aches or stiffness
  • Joint pain, stiffness, or swelling
  • Generalized swelling
  • Puffy face
  • Sugar and carbohydrate cravings
  • Heavy or irregular periods
  • Increased miscarriage risk
  • Infertility
  • Lack of ovulation
  • Depression or low mood
  • Anxiety
  • Impaired memory or “brain fog”
  • Slowed heart rate
  • High cholesterol
  • Loss of outer 1/3 of eyebrows

What Causes Hypothyroidism

Hashimoto’s Thyroiditis

90% of cases of hypothyroidism are due to an autoimmune attack on the thyroid gland by either thyroperoxidase antibodies (TPOAb) or by thyroglobulin antibodies (TgAb), a condition called Hashimoto’s thyroiditis. What this means is that the body creates immune cells that attack the gland so that function declines over time. This condition can be triggered by gluten in gluten-sensitive individuals. Similarly, in these people, gluten avoidance for at least 3 months may help lower antibody levels to a normal range.

Nutritional deficiencies

The thyroid gland needs iodine, selenium, zinc and thyroxine in order to function properly and create thyroid hormones. If you are deficient in any of these nutrients, you may experience symptoms of hypothyroidism. Iodine is found in iodized salt and sea vegetables (e.g. dulse flakes), selenium is abundantly found in Brazil nuts, and zinc is found in beef, cashews, pumpkin seeds, etc. Thyroxine, the amino acid that primarily makes up the thyroid hormones, is found in most sources of protein.

Conversion Disorder

In some people, the enzyme that is used to convert T4 into T3 doesn’t function properly and results in normal levels of TSH and T4 but severely deficient levels of T3. These individuals are often told by their doctors that their thyroid function is “normal” even though they do not feel normal! This is also why some people who are medicated with synthroid (thyroxine/T4) may feel like their medication is doing nothing for them.

Thyroid Hormone Resistance

Thyroid hormone resistance is similar to insulin resistance in diabetics. In this condition, the body’s cells are unresponsive to thyroid hormones. In these individuals, T3 and T4 levels can be normal but TSH levels are elevated.

Secondary or Tertiary Hypothyroidism

Secondary and tertiary hypothyroidism are extremely rare and are caused by disorders within the pituitary gland or hypothalamus in the brain. There are usually other concerning symptoms than just those associated with hypothyroidism in these cases.

Laboratory Testing

If you’ve ever been concerned about your thyroid function, you have probably had your TSH checked. If this comes back normal (between 0.30 and 5.5 mU/L), this is usually the extent of the testing you will receive. However, as mentioned above, proper thyroid function is dependent on adequate levels of multiple hormones, not just TSH. Further, there is a difference between having hormone levels in the normal range and having them in the optimal range. For example, not only do I like TSH to be under 5.5 mU/L, ideally the TSH is under 2.5 mU/L.

If I am concerned about a person’s thyroid function, I will start out by testing not only TSH but also levels of free T4 and T3 with our Comprehensive Thyroid Panel. Only with these three results are we able to determine whether you have adequate thyroid function. If these come back abnormal, the next step is to check the blood levels of TPOAb and TgAb, the antibodies responsible for Hashimoto’s disease.

After I gather a full picture of how the gland is functioning, a treatment plan created. Treatments can range from correcting nutritional deficiencies to lowering antibody levels to replacing any of the deficient hormones through medication.

This entire process is part of my Balanced Thyroid Program offered at A New Leaf Naturopathic Clinic.