Thyroid disorders are increasingly common. Yet, about half of sufferers remain undiagnosed due to improper testing and because initial signs and symptoms are vague, ambiguous, and often seen in various disorders. The underlying factor in very common disorders such as infertility, hair loss, irregular menses, constipation, fatigue, weight gain, elevated cholesterol, anemia, or depression may be a malfunctioning thyroid.
The most common thyroid problems involve abnormal production of thyroid hormones. Too much thyroid hormone results in a condition known as hyperthyroidism. Insufficient hormone production leads to hypothyroidism.
All types of hyperthyroidism are due to an overproduction of thyroid hormones, but the condition can occur in several ways:
- Graves' Disease - The production of too much thyroid hormone.
- Toxic Adenomas - Nodules develop in the thyroid gland and begin to secrete thyroid hormones, upsetting the body's chemical balance; some goiters may contain several of these nodules.
- Subacute Thyroiditis - Inflammation of the thyroid that causes the gland to "leak" excess hormones, resulting in temporary hyperthyroidism that generally lasts a few weeks but may persist for months.
- Pituitary gland malfunctions or cancerous growths in the thyroid gland - Although rare, hyperthyroidism can also develop from these causes.
Hypothyroidism, by contrast, stems from an underproduction of thyroid hormones. Since your body's energy production requires certain amounts of thyroid hormones, a drop in hormone production leads to lower energy levels. Causes of hypothyroidism include:
- Hashimoto's Thyroiditis - In this autoimmune disorder, the body attacks thyroid tissue. The tissue eventually dies and stops producing hormones.
- Removal of the thyroid gland - The thyroid may be surgically removed or chemically destroyed.
- Exposure to excessive amounts of iodide - Some cold and sinus medicines, the heart medicine amiodarone and X-ray dyes may occasionally cause hypothyroidism in certain patients, especially if you've had thyroid problems in the past.
Testing And Treatment Of Thyroid Disorders
Most physicians, including endocrinologists, rely on standard thyroid tests (generally TSH) to determine their patients' "proper" dose of thyroid replacement. The evaluation of a patient's signs and symptoms to determine the proper dose has been reduced to the point of being unimportant to most physicians.
Reliable studies like the one published in The British Medical Journal - "Are biochemical tests of thyroid function of any value in monitoring patients receiving thyroxine replacement?" have demonstrated that relying on standard thyroid tests to determine optimal doses of thyroid replacement is inaccurate. This will result in inadequate replacement for the majority of patients, such as exclusive uses of T4 preparations.
The authors of the above mentioned study measured thyroid stimulating hormone (TSH), free T4, free T3, total T4 and total T3, used a battery of clinical parameters and an exam by clinicians experienced in thyroid disease. They demonstrated that:
- TSH is a poor measure for estimating the metabolic severity of primary thyroid failure and/or a proper thyroid dose;
- these standard measurements are of little, if any, value in monitoring patients receiving thyroxine replacement;
- the poor diagnostic sensitivity and high false positive rates associated with such measurements render them virtually useless in clinical practice; and
- further adjustments to the dose should be made according to the patient's clinical response.
Many physicians and endocrinologists, feel that a suppressed TSH is an indication that the dose of thyroid should be reduced (except with thyroid cancer). While a suppressed TSH may be an indication the patient is hyperthyroid, this study found that was the case only 20% of the time.
In other words, doctors who make the assumption that a suppressed TSH means over-replacement and decrease the dose based on the suppressed TSH, will be wrong 80% of the time! This shocking reality happens because 80% of the time, a suppressed TSH was shown not to be an indication that the patient was hyperthyroid or receiving too much thyroid replacement.
Unfortunately, some doctors lack of ability or confidence to clinically evaluate a patient's thyroid status and lack understanding of the limitations of standard thyroid function tests, which has resulted in the majority of hypothyroid patients receiving inadequate doses of thyroid replacement.
The National Academy of Hypothyroidism
What Can Be Done About The Rise Of Thyroid Disorders