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Chapter One
Could You Have an Undiagnosed Thyroid Condition?
Knowledge is of two kinds: we know a subject ourselves,
or we know where we can find information about it.
—Samuel Johnson
The thyroid is a small bowtie or butterfly-shaped gland located in your neck around the windpipe, behind and below your Adam's apple area. The thyroid produces several hormones, but two are absolutely essential: triiodothyronine (T3) and thyroxine (T4). These hormones help oxygen get into your cells and are critical to your body's ability to produce energy. This role in delivering oxygen and energy makes your thyroid the master gland of metabolism.
The thyroid has the only cells in the body capable of absorbing iodine. It takes in the iodine obtained through food, iodized salt, or supplements, and combines that iodine with the amino acid tyrosine.The thyroid then converts the iodine/tyrosine combination into thehormones T3 and T4. The 3 and the 4 refer to the number of iodine molecules in each thyroid hormone molecule.
Of all the hormones produced by your thyroid when it is functioning properly, approximately 80% will be T4 and 20% will be T3. Of the two, T3 is the biologically active hormone—the one that actually has an effect at the cellular level. So while the thyroid produces some T3, the rest of the T3 needed by the body is actually formed when the body converts T4 to T3. Once released by the thyroid, theT3 and T4 travel through the bloodstream. The purpose is to help cells convert oxygen and calories into energy to serve as the basic fuel of your metabolism.
As mentioned, the thyroid produces some T3. But the rest of theT3 needed by the body is actually formed from the mostly inactive T4 by a process sometimes referred to as T4 to T3 conversion. This conversion can take place in the thyroid, the liver, the brain, and in other organs and tissues.
As T3 circulates through your bloodstream, it attaches to and enters your cells via receptor sites on the membrane of the cells. Once inside the cells, T3 increases cell metabolic rate, including body temperature, and stimulates the cells to produce a number of different hormones, enzymes, neurotransmitters, and muscle tissue. T3 also helps your cells use oxygen and release carbon dioxide, which helps smooth metabolic function.
So how does the thyroid know how much T4 and T3 to produce? The release of hormones from the thyroid is part of a feedback process. The hypothalamus, a part of the brain, emits thyrotropin-releasing hormone (TRH). The release of TRH tells your pituitary gland to in turn produce thyroid-stimulating hormone (TSH). ThisTSH that circulates in your bloodstream is the messenger that tells your thyroid to make the thyroid hormones T4 and T3, sending them into your bloodstream. When there is enough thyroid hormone, the pituitary makes less TSH, which is a signal to the thyroid that it can slow down hormone production. It's a smoothly functioning system when it works properly. When something interferes with the system and the feedback process doesn't work, thyroid problems can develop.
Prevalence
At minimum, experts estimate that there are 20 million thyroid sufferers in the United States, and 13 million of them are undiagnosed. The majority of people with thyroid conditions have Hashimoto's disease, an autoimmune condition that causes hypothyroidism—an underactivethyroid. Thyroid disease is actually the most common autoimmune condition in America today.
Women are seven times more likely than men to develop thyroid problems. Women face as much as a one in five chance of developing a thyroid problem during their lifetime. The risk of...
Author: Mary J. Shomon
Bio:
Diagnosed with a thyroid disease in 1995, Mary J. Shomon has transformed her health challenges into a mission as an internationally known patient advocate. She is the founder and editor in chief of several thyroid, autoimmune, and nutrition newsletters, as well as the Internet's most popular thyroid disease website, www.thyroid-info.com. She lives in Kensington, Maryland.















