Thyroid Gland Overview
A series of messages control the production of thyroid hormones, starting in the hypothalamus. When thyroid hormones are too low, the hypothalamus sends a message to the pituitary gland, which in turn produces Thyroid Stimulating Hormone (TSH) instructing the thyroid to become active. The thyroid uses iodine to combine with the amino acid called tyrosine, to produce two hormones called T3 (triiodothronine) and T4 (thyroxine). Approximately 80% of the hormones are in the form of T4, however T3 is about four times as strong as the T4 hormones, ultimately making them “balanced” in the blood stream.
The thyroid hormones regulate the metabolism of every cell in the body. Metabolism is the process of converting oxygen and food (calories) into energy. A fast metabolism can be an indication of hyperthyroidism, or too many thyroid hormones in the blood. Conversely, hypothyroidism, or too few thyroid hormones, may be the cause of a slow metabolism.
Doctors use blood tests to determine if the thyroid is operating properly. However, there is some question about the accuracy of these tests due to the interference caused by fluoride displacing the necessary iodine in the thyroid. Blood tests may show normal thyroid hormone levels when the reality is hypothyroidism. Basal body temperature is also valuable in determining the function of the thyroid, with a low temperature indicating hypothyroidism.
Hypothyroidism is a common problem of the thyroid. Some physicians estimate that as many as 90% of the population suffer from an underactive thyroid gland. Symptoms of hypothyroidism include fatigue, weight gain, dry or thinning hair, constipation, muscle cramps or aches, and irritability.
The thyroid also plays a role in controlling blood calcium levels by producing calcitonin, a hormone that counteracts parathyroid hormone. The parathyroid glands are four tiny glands usually located behind the thyroid. They produce parathyroid hormone, which is primarily responsible for regulating calcium in the blood. While the parathyroid glands are independent of the thyroid, their close proximity to each other can be an issue when diagnosing problems with either the thyroid or parathyroid glands.
Other problems that occur with the thyroid are goiters, Graves’ Syndrome, Hashimoto’s Thyroiditis, nodules and cancer. Iodine deficiency is also a problem of epidemic proportions when it comes to proper thyroid function. Iodine is deficient in our diets and is actually under attack in the human body by competition from toxic halogens such as fluoride, chlorine and bromide.
A nutritional diet and daily exercise are vitally important to maintaining a healthy thyroid. If you suspect problems with your thyroid, seek the help of a qualified endocrinologist.