The thyroid is a butterfly-shaped gland that is situated below and behind the larynx (Adam’s apple) and in front of the windpipe (trachea). The pituitary gland produces thyroid stimulating hormone (TSH) that directs the thyroid gland to make thyroid hormone. Thyroid hormone regulates the metabolic rate, the efficiency with which all the physical and chemical processes in the body transform foods into energy for both cellular building (anabolic) and cellular breaking down (catabolic) processes. If you were a car, your metabolic rate could be described as the gear you are in or your rpm’s
Deficiency of thyroid hormone is called hypothyroidism and it ranges from mild to severe. Inasmuch as thyroid hormone affects every organ, tissue, and cell in the body, disturbances in thyroid function result in many and varied symptoms. Some of the symptoms of hypothyroidism are the result of the build up of wastes in body tissues from sluggish metabolism. Some hypothyroidism is called Hashimoto’s thyroiditis, an autoimmune reaction caused by the body’s antibodies attacking the thyroid gland.
Low thyroid function can also occur as a result of treatments for hyperthyroidism or thyroid cancer, including radioactive iodine and surgical removal of the thyroid gland. Aging and toxicity, notably the toxicity from mercury, dioxin, Candida (yeast) toxins, and alcohol can also contribute. The use of some drugs, including lithium and amarodione, have been associated with hypothyroidism. A pituitary problem can also cause thyroid imbalances. Diabetics have a higher incidence of hypothyroidism than the general population. Similarly, if you have hardening of the arteries or a recent heart attack, you may well be deficient in thyroid hormone. Because many of the symptoms of low thyroid hormone levels are of a general nature (fatigue, obesity, constipation, dry skin), the diagnosis can be overlooked, often for years. If a person is deficient in thyroid hormone, the symptoms of deficiency will not respond satisfactorily to anything but appropriate replacement of the deficient hormone.
Subclinical hypothyroidism is a condition that occurs when many of the signs and symptoms of deficient thyroid hormone (see listing in this newsletter) are present, but the usual laboratory measurements of thyroid hormone are within the normal range. Special thyroid laboratory blood tests will often detect thyroid deficiencies in these individuals. Such patients may function or feel better if they take small doses of thyroid hormone.
We are descendants of people who survived, in part, because the metabolic rate can be lowered during famines, allowing survival on fewer calories. Any stress, not just famine, can result in this lowering of the metabolic rate to conserve calories. And that response can persist even after the stress has disappeared. This response contributes to the obesity that is characteristic of hypothyroidism.
For more information on the diagnosis and treatment of hypothyroidism, we suggest: Hypothyroidism: The Unsuspected Illness; Barnes, Broda O., M.D. and Galton, Lawrence; and Wilson’s Syndrome The Miracle of Feeling Well; E. Denis Wilson, M.D.