More than three quarters of the people suffering from an underactive thyroid don't know it and have never been treated — and this means some 8 million Americans.
If you are running on too little thyroid hormone, your whole metabolism is "low." You may feel run down, slow, depressed, sluggish, cold, and tired. Your hair may be brittle, your skin dry and itchy, your muscles crampy.
The most common cause of low thyroid production is an autoimmune disease called Hashimoto's thyroiditis in which your lymphocytes make antibodies which slowly and gradually disable the hormone-producing cells in your thyroid gland.
Diagnosis is easily made with a simple blood test, measuring the amount of thyroid stimulating hormone (TSH) from your pituitary gland. A high TSH shows that the pituitary is trying to tell your thyroid to raise your hormone level—and that it needs to be raised. If your TSH is high, other tests measuring thyroxine (T4) and other thyroid levels can sort out the severity of the condition.
Treatment is also straightforward. The missing thyroid hormone is replaced in pill form, usually as pure thyroxine. Once the body has the hormone it needs, you should feel well. Rechecking the TSH level periodically will tell whether your thyroid dose is right.
New research suggests that for some people a mixture of thyroid hormones (T4 and T3) may be better and help them feel more normal. This is a hot topic among thyroid researchers today so keep in touch with your doctor and check our website periodically for updates about this.
In rare cases, the pituitary gland is the problem, not the thyroid. Here treatment must be directed toward the pituitary in addition to supplying the needed thyroid hormone.
Iodine deficiency can be a cause of hypothyroidism and many serious physical and mental problems if the diet is deficient and iodine is not available through iodized salt and other sources. This is not a problem in the US and most developed countries, but worldwide it is the commonest cause of thyroid disease including hypothyroidism.
Older people are at risk of having this problem occur unrecognized later in life. Seventeen percent (17%) of women and 8% of men have hypothyroidism by age 60. The cause is still Hashimoto's disease in most cases, however, this is especially common in older folks.
Newborns are now tested in the US and most developed countries so thyroid difficulties are caught at birth. One in 3500 babies born in the US today have no thyroid gland and needs treatment by 2 months of age to prevent permanent mental and physical damage. Fortunately, an under-performing or missing thyroid gland can be supplemented at once with the needed thyroxine.
Other family members may share the genes that leads to hypothyroidism. This means they are more likely to have thyroid problems, and also thyroid-related conditions like diabetes, pernicious anemia, depression, arthritis, a variety of skin disorders, and even carpal tunnel syndrome.