The thyroid gland is responsible for our metabolism, controlling how quickly the body uses energy. It is one of the largest endocrine glands, comprised of two lobes and a bridge connecting them. It is located in the neck, below the “Adam’s apple”.
Hyperthyroidism occurs when the body produces too much thyroid hormone, leading to weight loss, insomnia, anxiety and heat intolerance.
Hypothyroidism is much more common, particularly in women. The low production or conversion of thyroid hormone leads to symptoms of fatigue, sleepiness, and weight gain. The fatigue can be so debilitating that individuals sleep for longer than 24 hours.
When patients are fatigued, a blood test for Thyroid-Stimulating Hormone (TSH) is ordered . TSH, produced by the pituitary gland, controls thyroid hormone output . Its release causes the production and release of T4 by the thyroid gland, which is converted to the active thyroid hormone form, T3, by removing an iodine molecule.
TSH and thyroid hormone have a negative feedback relationship. When thyroid hormone is low, TSH production and release is increased to stimulate production of T4, as is the case in hypothyroidism.
Standard laboratory tests describe a normal TSH range of 0.35-5.00 mIU/L. Naturopathic doctors see this range as being too wide for useful diagnosis of thyroid disease. Clinical experience demonstrates that a TSH above 2.5 mIU/L indicates a problem with thyroid hormone production as many patients experience hypothyroid symptoms even when their TSH is within normal limits.
fatigue, loss of energy, sleepiness weight gain, inability to lose weight decreased appetite cold intolerance dry skin hair loss depression, emotional lability impaired memory, difficulty concentrating constipation menstrual irregularities
Another concern about thyroid disease screening, is that it measures only TSH, not T3, T4 or reverse T3. Although TSH can be in the normal range, T4 may be too high and T3 may be too low, indicating improper conversion to the active form. In addition, T4 may be converted to reverse T3, which is similar to T3, except the iodine has been removed from a different position, rendering it inactive. Reverse T3 is made in times of stress and systemic illness as a way to conserve energy. Without seeing all of these values, hypothyroidism can go undiagnosed.
Stress is also a factor in thyroid health. Under times of chronic and high stress, the production of cortisol requires tyrosine, an amino acid required for thyroid hormone production. Cortisol uses the body’s available tyrosine, leaving little for T4 production, leading to reduced thyroid function.
Although hypothyroidism is common, medication may not always be the answer. If the hypothyroidism is caused by a systemic illness, or the real culprit is chronic stress, these must be treated first. In addition, there are key nutrients that support optimal thyroid function, such as zinc, copper, iron, selenium and B12. Furthermore, herbs can stimulate T4 production and the conversion to T3. Lastly, avoiding soy, almonds and Brassica vegetables (broccoli, cabbage, brussel sprouts) is advisable for people with hypothyroidism as these foods can inhibit thyroid gland function.
If you have been more fatigued lately and/or despite exercise and healthy eating are unable to lose weight, your thyroid function may be the reason.
Dr. Klemm is the Naturopathic Doctor at Markham Integrative Medicine. One of her main areas of interest is hormone health. To schedule an appointment with Dr. Klemm, phone (905)294-2335.