http://www.icnr.com/articles/hypothyroidism-causes-symptoms-and-remedies.html

"There are seven principal reasons why there is a high incidence of under-active thyroid in America.

First, the wide spread use of chlorine to disinfect our public water exposes everyone to chlorine. Chlorine can interfere with proper thyroid conversion of the thyroid hormone T4 to T3 (the biologically active form of the hormone) and result in hypothyroidism.

Second, toxic competing halogens (chlorine, bromine, fluorine and perchlorate) have dramatically increased. These halogens inhibit thyroid hormone production. Halogens appear in our food, water, medications and environment as chlorides, bromides and fluorides and they selectively attach to your Iodine receptors, preventing Iodine from working. Bromine has replaced Iodine as a bleaching agent in breads and bake goods. Fluoride concentrations in toothpastes can be as high as 1500 parts per million.

Third, increased exposure to pesticides used on foods specifically methyl bromide, used mainly on strawberries further reduces thyroid function.

Fourth, mercury dental filling leak mercury 24/7, which then migrates through the lymphatic system to your thyroid. Mercury is the second most toxic substance on this planet second only to plutonium. Mercury has an affinity for nerve tissue and destroys the tubulin (fatty tissue that surrounds the nerve fiber). Also mercury toxicity can mimic any disease process.

Fifth, consumption of polyunsaturated fats (PUFA) such as canola oil, flax seed oil, soy oil, safflower oil, sunflower oil, and other polyunsaturated vegetable oils will suppress thyroid function. What's wrong with vegetable oils? The main problem is that polyunsaturated oils contain long-chain fatty acids, which are extremely fragile and unstable. "The unsaturated oils in some cooked foods become rancid in just a few hours even when refrigerated," says Ray Peat, P.h.D. "and that's responsible for the stale taste of leftover foods. Eating slightly stale food with polyunsaturated oils isn't more harmful than eating the same oils when fresh, since the oils will oxidize at a much higher rate once they are in the body. As soon as a polyunsaturated vegetable oil enters the body, it is exposed to temperatures high enough to cause its toxic decomposition, especially when combined with a continuous supply of oxygen and catalysts such as iron." Even if you stop eating them, polyunsaturated fatty acids remain stored in tissue, only to be released during times of stress or fasting—including the middle of the night, when one is asleep. Although PUFAs damage every part of the body, the endocrine system, especially the thyroid, is particularly vulnerable. A slow metabolism, low energy, and sluggish thyroid often accompany the consumption of vegetable oils.

Sixth, iodine deficiency is one of the three most common nutritional deficiencies, along with magnesium and vitamin D. In the U.S. population, there was a 50 percent reduction in urinary iodine excretion between 1970 and 1990. The Japanese consume 89 times more iodine than Americans due to their daily consumption of sea vegetables, and they have reduced rates of many chronic diseases, including the lowest rates of cancer in the world. The RDA for iodine in the U.S. is a meager 150 mcg/day, which pales in comparison with the average daily intake of 13,800 mcg/day for the Japanese.

Seventh, although not recognized by most health care practitioners vaccinations represent a major potential initiator for causing hypothyroidism. Vaccines such as tetanus, diphtheria, pertussis and others are being trapped by the thyroid and provide one cause for autoimmune diseases. Viewed as foreign bodies, these vaccines create an inflammatory state, which interferes with normal thyroid function.
Thyroid homeopathic remedies

The key to properly treating the thyroid is to diagnose what the underlying reasons are for its dysfunction. Heavy metals specially mercury, pesticides, chemicals, nutritional deficiencies specially iodine, vaccinations, infections (viral, bacterial, fungal, mold) and radiation are some of the issues that have to be considered. Once the causative factor(s) are recognized, a comprehensive detoxification program is required. Reducing the burden will enhance nutritional, homeopathic or even a natural thyroid hormone therapy.

One product that has clinical merit is Vibren's homeopathic Thyroid ($24.95). It has a proprietary blend of remedies plus supports tissue function. Its multiple potencies (3x, 6x, 9x and 12x) increase its effectiveness by activating the various cell structures. This homeopathic remedy will be of particular interest to those patients who are taking prescription Armor or other natural thyroid hormones and are unable to obtain their medications because of unavailability.

Other homeopathic substances that may be beneficial include Lycopus, Ignatia, Spigelia, Iodum, Spongia tosta, Baryta carbonica, Ammonium muriaticum, Fucus, Thyroidinum, Badiaga, Calcarea iodatum, Ferru iodatum, Sulfuricum iodatum and Arsenicum album.
Hypothyroid Symptoms

One of the most comprehensive books on hypothyroidism is, "Hypothyroidism Type 2, by Mark Starr, MD. Doctor Starr provides a list of clinical symptoms he observed in his patients plus references the original research of Eugene Hertoge, a Belgium medical doctor who connected many symptoms to a low thyroid: depression, anxiety, panic attacks, chronic fatigue, weakness, TMJ Dysfunction, cold hands and feet, thinning hair, coarse and dry hair, dizziness, ringing in the ears, mental fog, insomnia, poor memory and memory loss, heart palpitations, brittle nails, increase incidence of tooth decay, constipation, poor digestion, osteoporosis, acne, itchy skin, rashes, weak ligaments, heavy menstrual bleeding, decreased libido, muscle cramps and frequent muscle aches, weak immune system, elevated cholesterol, high blood pressure and pale skin color. Doctor Starr also provides a thorough list of infant hypothyroid symptoms. Included in his list are edema (swelling), poor feeding, stomach distention, blotchy skin, respiratory distress, decreased stool frequency, poor sucking ability and macroglossia (large tongue) to name a few.
Prevalence

Hypothyroidism is far more prevalent than once thought. The latest estimates are that 20 million Americans have hypothyroidism, but the actual numbers are probably higher.

In 1995, researchers studied 25,862 participants at the Colorado statewide health fair. They discovered that among patients not taking thyroid medication, 8.9 percent were hypothyroid (under-active thyroid) and 1.1 percent were hyperthyroid (over-active thyroid). This indicates 9.9 percent of the population had a thyroid problem that had most likely gone unrecognized. These figures suggest that nationally, there may be as many as 13 million Americans with an undiagnosed thyroid problem. [1]

In her book Living Well With Hypothyroidism: What Your Doctor Doesn't Tell You ... That You Need to Know, Mary Shomon quotes endocrinologist Kenneth Blanchard, M.D., of Lower Newton Falls, Massachusetts as saying, "The key thing is . . . doctors are always told that TSH is the test that gives us a yes or no answer. And, in fact, I think that's fundamentally wrong. The pituitary TSH is controlled not just by how much T4 and T3 is in circulation, but T4 is getting converted to T3 at the pituitary level. Excess T3 generated at the pituitary level can falsely suppress TSH." [2] Hence, many people who are simply tested for TSH levels and are found to be within "normal" range are, in fact, suffering from thyroid problems that are going undetected.

Ridha Arem, MD, Associate Professor of Medicine in the Division of Endocrinology and Metabolism at Baylor College of Medicine, agrees. He says that hypothyroidism may exist despite "normal range" TSH levels. In his book The Thyroid Solution he says:

Many people may be suffering from minute imbalances that have not yet resulted in abnormal blood tests. If we included people with low-grade hypothyroidism whose blood tests are normal, the frequency of hypothyroidism would no doubt exceed 10 percent of the population. What is of special concern, though, is that many people whose test results are dismissed as normal could continue to have symptoms of an under active thyroid. Their moods, emotions, and overall well-being are affected by this imbalance, yet they are not receiving the care they need to get to the root of their problems. Even if the TSH level is in the lower segment of normal range, a person may still be suffering from low-grade hypothyroidism. [3]

Unfortunately much of Dr. Hertoge's original research is not present in "modern" endocrinology textbooks. As a result most physicians are unaware of the many symptoms associated with hypothyroidism and cannot properly diagnose the problem. Many people suffer needlessly because their symptoms go unrecognized. In addition, our toxic environment which includes dioxins, PCBs, chlorinated drinking water, brominated breads, trans fats, fungicides (hexachlorobenzene HCB), phthalates (used to soften plastics), fluoridated water and toothpaste plus mercury fillings and mercury vapor from burning coal for power plants all contribute to the increased prevalence of hypothyroidism. The educated physician and consumer must understand the necessity to detox their body and specially their thyroid prior to any attempt to stimulate its function. Allowing mercury and other heavy metals, pesticides, childhood vaccines, infections and chemicals like fluoride to remain trapped within the thyroid will prevent normal function even if patients take thyroid hormone, kelp, iodine or homeopathic remedies or other nutritional support. One must detox on a regular basis with natural chelating agents just to help keep the levels down. Such antioxidants as SOD (superoxide dismutase), glutathione, natural B-complex vitamins, turmeric, chlorella, cilantro, manganese, selenium, organic iron, potassium iodine and sulfur bearing amino acids are all essential substances that are effective in removing toxic chemicals.

The thyroid gland is a nutritionally dependent organ. It requires such nutrients as selenium, Iodine (12.5 to 50 mg. range), amino acids Taurine (200 to 1000 mg. per day is the recommended dosage.) and L-tyrosine, Forskolin is an extract of an Ayurvedic herb that resensitizes cell receptors; folic acid (400 mcg), zinc (60 mg), copper and vitamins B6 and B12, iron, vitamin E, D, essential fatty acids and manganese."