The thyroid gland needs iodine, an element in soil and water, to function properly. Most people in the United States take in enough iodine by using iodized salt, eating fish and vegetables and drinking water and milk. When thyroxin levels are low, the pituitary responds by releasing TSH in larger quantities. As a result, high TSH is the best indication of an underactive thyroid.
Over a 10-year period, according to one study, persons with antibodies but normal thyroid functions had an annual risk of two to four percent of developing full-blown hypothyroidism. Thyroid abnormalities are rare during pregnancy; when it does occur, however, untreated hypothyroidism often results in some degree of impairment in the development of the fetus.
After giving birth, about 5 to 10 percent of women develop postpartum thyroid disease, with symptoms sometimes similar to those of postpartum depression. Postpartum hypothyroidism may be characterized by fatigue, a feeling of exhaustion and weight gain.
Simple or nontoxic goiter is an enlargement of the thyroid that is not related to cancer or other disease. The thyroid might enlarge in an effort to compensate for a lack of iodine in the diet or an excessive consumption of foods that interfere with thyroid synthesis.
Other causes of low thyroid function are environmental or medical exposure to radiation, inherited disorders and surgical removal of the gland or radiation to reduce its size. Many patients who develop thyroid problems don’t have any of these risk factors, however. A number of drugs can also interfere with thyroid function. Medications to watch for include lithium and phenylbutazone.
Diagnosis
Diagnosis is simple. A blood test can identify low levels of thyroxine and elevated levels of TSH (thyroid stimulating hormone). And once identified low thyroid levels can be corrected with daily doses of levothyroxine.
Symptoms of low thyroid hormone levels may lead an individual to ask for a screening test. Bremo Pharmacy offers a quick fingerstick thyroid screening test. With one fingerstick and in ten minutes, you can find out if you should see your doctor about this condition. {{{For details, go to www.bremorx.com}}}. Laboratory screening of the TSH level, along with a health professional evaluation, is needed to confirm a thyroid condition.
Symptoms
Symptoms of an underactive thyroid are listed below. A given individual may experience only a selected few of these symptoms, however, or none at all, particularly in the early stages when increased levels of TSH keep thyroid hormones at a somewhat normal level.
- Swollen/puffy hands, face
- Brittle nails
- Weight gain or trouble losing weight
- Constipation
- Irregular or heavy menstrual periods
- Infertility
- Hoarse or raspy voice
- Slower speech
- Slow heart beat
- Enlarged thyroid gland (front of neck)
- High cholesterol level
- Hair loss from your head or eyebrows
- Hair graying prematurely
- Hearing loss
- Feeling very tired
- Feeling depressed
- Having trouble concentrating
- Slower thinking
- Having trouble remembering things
- Paler skin than usual
- Very dry skin
- Feeling cold all over or cold hands, sensitive to cold
- Muscle and/or joint pain
- Slower reflexes
Consequences
Mild hypothyroidism may or may not be treated. In most cases, however, low levels of thyroid hormones will eventually lead to high blood pressure, elevated cholesterol, an enlarged heart and congestive heart failure. Older adults may become increasingly slow mentally and physically–an acceleration of what some might consider normal aging. The most serious, but rare, consequence is myxedema, a life-threatening coma–usually a result of years of undiagnosed hypothyroidism.
Subclinical hypothyroidism as discovered through screening tests but without severe symptoms is believed to be a risk factor for atherosclerosis and heart attack in women age 60 and over. The Rotterdam Study found subclinical hypothyroidism in 10.8 percent of its cohort of 1,149 older women. Women with this thyroid disorder had a greater likelihood of having atherosclerosis of the aorta and of suffering a heart attack. Additional research is needed to confirm results from this cross-sectional study.
Low thyroid function can create fertility problems for women wishing to conceive. In addition, some studies suggest that women with hypothyroidism (low thyroid function) have up to four times greater risk of miscarriage during the second trimester.
Women planning to become pregnant are advised to have a TSH test to screen for thyroid problems as part of pre-pregnancy testing. Pregnant women already being treated for low thyroid function should be carefully monitored during pregnancy and may require an increase in thyroid medication.
Treatment
When hypothyroidism is detected, doctors treat it by prescribing the synthetic thyroid hormone, levothyroxine (Levothyroid, Synthroid) to restore normal blood levels of T3 and T4. In most cases, the patient must take the medication for the rest of her life.
One of the most widely prescribed drugs in the country, levothyroxine is relatively inexpensive and has virtually no side effects if used in the proper dose. Some rather severe effects can occur if the dose is too high, however, so doctors usually start low and follow up with TSH tests every four to eight weeks until the right dose is determined. The drug is best absorbed when taken on an empty stomach, but taking it after eating is better than forgetting to take it altogether.
Within a few weeks, most patients note an improvement in their energy level and the way they feel. As one man put it, “I never knew I had symptoms until I discovered how much better I felt when they were gone.”
When a person takes thyroid medication as a treatment for hypothyroidism, the physician needs to monitor thyroid levels to ensure that they fall within the normal range. Too high a replacement dose can cause heart rhythm problems, especially atrial fibrillation, and can compromise bone density, causing osteoporosis.
Drugs most likely to interact negatively with thyroid medications include anticonvulsants, certain antacids, warfarin, digoxin and rifampin. Supplements such as ferrous sulfate, soy, bugleweed and lemon balm may decrease the effectiveness of thyroid replacement medications.
Hypothyroidism is common and easy to treat. Regular screening and attention to the potential symptoms are two great ways to detect the disorder. Treatment may prevent long-term problems that go with the disorder and alleviate uncomfortable symptoms.
2008
Michelle Herbert Thomas, PharmD, CDE
Clinical Director, Richmond Apothecaries, Inc.
