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Overview |
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Definition |
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Hypothyroidism occurs when the thyroid gland produces too little thyroid
hormone, when there is decreased conversion from T4 to T3, when there is an
overproduction of reverse T3 (Wilson's syndrome), or when the body is not
efficiently using thyroid hormone. It can take several forms.
- In Hashimoto's thyroiditis, the most common type, the gland shrinks
and loses its function.
- Post-therapeutic hypothyroidism may follow overzealous treatment for
hyperthyroidism (excess production of thyroid hormone). Medical and surgical
treatments for hyperthyroidism can leave patients' thyroids incapable of
producing enough thyroid hormone.
- Goitrous hypothyroidism results from an extreme shortage of iodine in
the diet. Almost unknown in the United States since the introduction of iodized
salt, it produces a goiter in the neck.
Other types of hypothyroidism can stem from inherited enzymatic deficiencies
or the failure of other glands in the body. According to some estimates, as many
as 11 million Americans suffer some degree of hypothyroidism. However, the
majority of those cases go undiagnosed.
Hypothyroidism can occur in either sex at any age, although middle-aged women
are most commonly affected. Note that infants, adolescents, and adults show
different sets of symptoms. The disease has a wide variety of symptoms, and they
often reveal themselves slowly and subtly. Untreated, hypothyroidism can cause
anemia, a low body temperature, heart failure and, ultimately, a condition known
as myxedema coma. This type of coma, triggered by exposure to cold, infection,
or drugs such as sedatives, is potentially fatal. It leads to a slowdown in
breathing, seizures, and a reduction in the flow of blood to the brain. Myxedema
coma is extremely rare in warm climates, but not uncommon in cold
regions. |
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Etiology |
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- In Hashimoto's thyroiditis, often called primary hypothyroidism, an
autoimmune response occurs in which antibodies in the blood destroy tissues in
the thyroid gland. As a result, the thyroid decreases in size and reduces its
production of thyroid hormones.
- Post-therapeutic hypothyroidism results from the treatment of
hyperthyroidism with radioactive iodine or surgical removal of part or all of
the thyroid gland. The treatment can leave the patient's thyroid unable to
produce sufficient amounts of thyroid hormone.
- Goitrous hypothyroidism is caused by a lack of iodine in the diet, a
problem in some developing countries. (The thyroid requires a steady supply of
iodine to operate correctly.)
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Risk Factors |
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- Treatment for hyperthyroidism
- Chronic lack of iodine in the diet
- Inherited enzymatic defects
- For women, reaching middle
age
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Signs and Symptoms |
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- Slow pulse
- Lethargy
- Hoarse voice
- Slowed speech
- Puffy face
- Loss of eyebrows from the sides
- Drooping eyelids
- Intolerance to cold
- Weight gain
- Constipation
- Dry, scaly, thick, coarse hair
- Raised, thickened skin over the shins
- Carpal tunnel syndrome
- Confusion
- Depression
- In children, growth retardation, delayed teething, and mental
deficiency
- Dementia
- Headaches
- Menstrual cramps or other menstrual
disorders
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Differential
Diagnosis |
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- Euthyroid sick syndrome
- Depression
- Alzheimer's disease or other types of dementia
- Carpal tunnel syndrome
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Diagnosis |
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Physical Examination |
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Patients typically report muscle aches and the inability to stay warm in cool
or cold temperatures. Tests of reflexes indicate brisk contraction and slow
relaxation times. As symptoms progress, patients show puffy faces, dry,
thickened skin, hoarseness, and hearing loss. The palms and soles have slightly
orange hues, evidence of carotene deposits. The heart is
enlarged. |
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Laboratory Tests |
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Blood tests may show decreased levels of thyroid hormone, increased
thyroid-stimulating hormone, and the presence of autoantibodies, differentiating
between primary and secondary hypothyroidism. Patients with primary
hypothyroidism, for example, will not respond to radioactive iodine uptake
tests, while most of those with secondary hypothyroidism will show a brisk
response. Blood tests can also indicate the presence of anemia, a symptom of
untreated hypothyroidism.Hypercholesterolemia may be found with
hypothyroidism. |
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Other Diagnostic
Procedures |
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When necessary, perform two radioactive iodine uptake tests four days
apart. |
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Treatment Options |
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Treatment Strategy |
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Providers can prescribe several thyroid hormones as replacement therapy.
Typically, condition improves within two to three weeks of the start of daily
hormone therapy, and all symptoms disappear within a few months. However,
patients must continue this treatment for the rest of their
lives. |
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Drug Therapies |
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Health care providers must initially choose between synthetic preparations of
the human thyroid hormone and dried forms of animal thyroid hormone. Providers
generally prefer synthetic versions of thyroxine, liothyronine, or combinations
of the two. They typically prescribe 100 to 125 mcg of the medication daily, to
be taken orally. Evidence suggests that patients absorb about 90% to 95% of the
dose.
Key to effective treatment is calibration of the medication. Particularly in
older patients, treatment should start with small doses of thyroid hormone.
Providers then gradually increase the dose until the individual's blood level of
thyroid-stimulating hormone returns to normal. With appropriate calibration of
doses, the patient will reach this stage about eight weeks after the start of
daily therapy.
Specialists recommend that providers not prescribe liothyronine alone over
long periods. It tends to cause chemical hyperthyroidism for at least several
hours per day, thereby exposing the patient to above normal cardiac risks. Since
myxedema coma represents an emergency situation, providers should administer
replacement hormones intravenously. |
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Complementary and Alternative
Therapies |
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Thyroid function can be effectively supported with nutrition and herbs,
although concurrent treatment with conventional medicine may be necessary in
moderate to severe cases. |
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Nutrition |
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Avoid foods that suppress thyroid function, including broccoli, cabbage,
brussels sprouts, cauliflower, kale, spinach, turnips, soybeans, peanuts,
linseed, pine nuts, millet, cassava, and mustard greens. Avoid refined foods,
dairy products, wheat, caffeine, and alcohol.
- Essential fatty acids (1,000 to 1,500 mg bid) are necessary for
hormone production. It may be wise to avoid flaxseed oil due to high levels of
cyanogenic glycosides. A better choice for omega-3 oils for the hypothyroid
patient would be cold-water fish oils or borage oil.
- Vitamin C (1,000 mg tid to qid), vitamin A (10,000 to 25,000 IU/day),
B complex (50 to 100 mg/day), augmented with vitamins B2 (riboflavin, 15 mg), B3
(niacin, 25 to 50 mg), and B6 (pyridoxine, 25 to 50 mg), selenium (200 mcg/day),
iodine (300 mcg/day), vitamin E (400 IU/day), and zinc (30 mg/day) are necessary
for thyroid hormone production.
- L-tyrosine (500 mg bid to tid) also supports normal thyroid function.
In a small percentage of patients it may cause caffeine-like symptoms. Patients
with insomnia should avoid taking L-tyrosine in the evening. (May rarely
exacerbate hypertension.)
- Calcium (1,000 mg/day) and magnesium (200 to 600 mg/day) are
cofactors for many metabolic processes.
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Herbs |
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Herbs are generally a safe way to strengthen and tone the body's systems.
Ascertain a diagnosis before pursuing treatment. Herbs may be used as dried
extracts (capsules, powders, teas), glycerites (glycerine extracts), or
tinctures (alcohol extracts). Unless otherwise indicated, teas should be made
with 1 tsp. herb per cup of hot water. Steep covered 5 to 10 minutes for leaf or
flowers, and 10 to 20 minutes for roots. Drink 2 to 4 cups/day.
A combination that would support thyroid function includes herbs rich in
minerals. Combine equal parts of the following herbs for a tea (3 to 4 cups/day)
or tincture (20 to 30 drops tid). Horsetail (Equisetum arvense),
oatstraw (Avena sativa), alfalfa (Medicago sativa), and gotu
kola (Centella asiatica).
Seaweeds such as kelp (Laminaria hyperborea), bladderwrack (Fucus
vesiculosus), Irish moss (Chondrus crispus) may be taken as foods or
in capsule form due to their salty and unfamiliar taste. Many patients would not
tolerate the seaweed taste in a tea beverage.
Coleus foreskohlii (1 to 2 ml tid) stimulates thyroid function with an
increase in thyroid hormone production. Also, herbs such as guggul
(Commiphora mikul, 25 mg of guggulsterones tid) and hawthorn
(Crataegus monogyna, 500 mg bid) are taken to counteract
hypercholesterolemia which often attends hypothyroidism. |
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Homeopathy |
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For patients that do not want to take whole tissue glandulars, homeopathic
glandulars are available for hypothyroidism. |
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Physical Medicine |
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Contrast hydrotherapy to the neck and throat may stimulate thyroid function.
Alternating hot and cold applications brings nutrients to the site and diffuses
metabolic waste from inflammation. The overall effect is decreased inflammation,
pain relief, and enhanced healing. Alternate three minutes hot with one minute
cold. Repeat three times to complete one set. Do two to three sets/day.
Exercise helps sensitize thyroid gland to hormones and improves its function.
Stress reduction techniques such as yoga, meditation, or tai chi help to lower
cortisol levels. High cortisol levels may decrease T3/reverse T3
ratios. |
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Acupuncture |
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Acupuncture may be helpful in correcting hormonal imbalances and addressing
underlying deficiencies involved in hypothyroidism. |
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Massage |
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Therapeutic massage may be useful in relieving stress, improving circulation,
and increasing the overall sense of well-being. |
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Patient Monitoring |
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Monitor patients carefully during and after any treatment.
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Other
Considerations |
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Prevention |
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A diet using small amounts of iodized salt may help prevent goitrous
hypothyroidism. |
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Complications/Sequelae |
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Watch out for brief swings into hyperthyroidism with certain
treatments. |
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Prognosis |
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Expect to see beneficial effects of hormone replacement therapy within two to
three weeks of starting the course of treatment. Symptoms should disappear
within a few months, by which time patients will have settled into a maintenance
dose of hormone. |
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Pregnancy |
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Thyroid testing during pregnancy may have variable and unreliable results.
Mild pathology may not be detected until after pregnancy. Thyroid treatment in
pregnancy should be done with the supervision of a
physician. |
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References |
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Bartram T. Encyclopedia of Herbal Medicine. Dorset, England: Grace
Publishers; 1995:304.
Berkow R. Merck Manual. 16th ed. Whitehorse Station, NJ: The Merck
Publishing Group; 1992.
Murray MT, Pizzorno JE. Encyclopedia of Natural Medicine.
2nd ed. Rocklin, Calif: Prima Publishing;
1998:386-390. |
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Copyright © 2000 Integrative Medicine
Communications This publication contains
information relating to general principles
of medical care that should not in any event be construed as specific
instructions for individual patients. The publisher does not accept any
responsibility for the accuracy of the information or the consequences arising
from the application, use, or misuse of any of the information contained herein,
including any injury and/or damage to any person or property as a matter of
product liability, negligence, or otherwise. No warranty, expressed or implied,
is made in regard to the contents of this material. No claims or endorsements
are made for any drugs or compounds currently marketed or in investigative use.
The reader is advised to check product information (including package inserts)
for changes and new information regarding dosage, precautions, warnings,
interactions, and contraindications before administering any drug, herb, or
supplement discussed herein. | |