Getting Down to Thyroid Basics

by Mary Shomon

Part 1
Where is the Thyroid and What Does it Do?
Causes of Thyroid Disease
Part 2
Hypothyroidism
Part 3
Hyperthyroidism
Goiter and Thyroid Nodules
Thyroid Cancer
Part 4:
When Symptoms Don't Go Away
Can You Prevent Thyroid Disease?
Part 5:
Resources / More Information


More than 10 million Americans have been diagnosed with thyroid disease, and another 13 million people are estimated to have undiagnosed thyroid problems in the U.S. alone. Frequently misunderstood, and far too often overlooked and misdiagnosed, thyroid disease can affect almost every aspect of health, so understanding more about the thyroid, and the symptoms that occur when something goes wrong with this small gland, can help you protect or regain good health health.

A February, 2000 research study found that the estimated number of people with undiagnosed thyroid disease may be 10 percent -- a level that is double what was previously thought. This may mean as many as 13 million Americans are currently undiagnosed. For women, the risk is even higher. A woman faces as high as a one in five chance of developing thyroid problems during her lifetime. That risk increases with age and for those with a family history of thyroid problems.

Where is the Thyroid and What Does it Do?

Your thyroid is a small bowtie or butterfly-shaped gland, located in your neck, wrapped around the windpipe, and is located below the Adam's Apple area. The thyroid produces several hormones, of which two are key: triiodothyronine (T3) and thyroxine (T4).

The thyroid has cells that are the only cells in the body's capable of absorbing iodine. The thyroid 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 the hormones T3 and T4. The "3" and the "4" refer to the number of iodine molecules in each thyroid hormone molecule.



When it's in good condition, of all the hormone produced by your thyroid, 80% will be T4 and 20% T3. T3 is considered the biologically more active hormone -- the one that actually functions at the cellular level -- and is also considered several times stronger than T4.

Once released by the thyroid, the T3 and T4 travel through the bloodstream. The purpose is to help cells convert oxygen and calories into energy.

As mentioned, the thyroid produces some T3. But the rest of the T3 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 of T4 to T3 can take place in some organs other than the thyroid, including the hypothalamus, a part of your brain.

The thyroid is part of a huge feedback process. The hypothalamus in the brain releases something called Thyrotropin-releasing Hormone (TRH). The release of TRH tells the pituitary gland to release something called Thyroid Stimulating Hormone (TSH). This TSH, circulating in your bloodstream, is what tells the thyroid to make thyroid hormones and release them into your bloodstream.

Causes of Thyroid Disease

What causes thyroid problems? Besides the treatments mentioned above, there are other factors that can contribute to the development of various thyroid problems:

• Exposure to radiation, such as occurred after the Chernobyl nuclear plant accident
• Overconsumption of isoflavone-intensive soy products, such as soy protein, soy capsules, soy powders
• Some drugs, such as lithium and the heart drug cordarone, can cause hypothyroidism.
• An overconsumption or shortage of iodine in the diet can also trigger some thyroid problems. (This also applies to iodine-containing supplements, such as kelp and bladderwrack.)
• Radiation treatment to my head, neck or chest. Radiation treatment for tonsils, adenoids, lymph nodes, thymus gland problems, or acne
• "Nasal Radium Therapy," which took place during the 1940s through 1960s, as a treatment for tonsillitis, colds and other ailments, or as a military submariner and/or pilot who had trouble with drastic changes in pressure
• Overconsumption of uncooked "goitrogenic" foods, such as brussels sprouts, broccoli, rutabaga, turnips, kohlrabi, radishes, cauliflower, African cassava, millet, babassu (a palm-tree coconut fruit popular in Brazil and Africa), cabbage and kale

You have a higher risk of developing thyroid disease if: …You have a family member with a thyroid problem …You have another pituitary or endocrine disease …You or a family member have another autoimmune disease …You've been diagnosed with Chronic Fatigue Syndrome …You've been diagnosed with Fibromyalgia …You're female …You're over 60 …You've just had a baby …You're near menopause or menopausal …You're a smoker …You've been exposed to radiation …You've been treated with lithium …You eat too much soy foods …You've been exposed to certain chemicals (i.e., perchlorate, fluoride)

Part 2 > Hypothyroidism

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