Understanding Thyroid Problems - Treatment

How Do I Know If I Have a Thyroid Problem?

Your doctor can diagnose hyperthyroidism and hypothyroidism by testing the levels of thyroid hormones in your blood. Doctors measure hormones secreted by the thyroid itself, as well as thyroid-stimulating hormone (TSH), a chemical released by the pituitary gland that triggers hormone production in the thyroid.

When you are hypothyroid, higher quantities of TSH are circulating in your blood as your body attempts to foster increased production of thyroid hormones.  The reverse is true with hyperthyroidism, in which TSH levels are below normal and circulating thyroid-hormone levels are high.

To determine the cause of hyperthyroidism, doctors often use radioactive iodide uptake tests, which track the amount of iodide absorbed by the thyroid gland. Iodide, obtained from the foods we eat, is a key ingredient in the manufacture of thyroid hormone, so the amount of iodide the thyroid absorbs is a reliable indicator of how much hormone the gland is producing.  For this test, you must swallow a small amount of radioactive iodide in liquid or capsule form.  After a predetermined wait, the doctor places an instrument over your neck to measure how much of the radioactive iodide has gathered in your thyroid.

If the results of this test suggest that the gland is collecting excessive amounts of iodide, the doctor may then conduct a radioactive iodide uptake scan. In this test, the doctor uses a special film to create a picture that shows the exact location of the radioactive iodide in your thyroid gland.  The scan will reveal, for example, if the iodide is collecting in adenomas, indicating that the nodules are responsible for the excess hormone.  If the scan shows that the iodide is spread equally throughout the tissue, the whole thyroid is involved in the excess production.

Some doctors believe that blood tests may not be sensitive enough to detect milder forms of hypothyroidism.  Instead, they advocate monitoring your body's basal (resting) temperature.  To track your basal temperature accurately, you must closely follow certain guidelines: 

• Shake the thermometer below 95° F at night and place it where you can reach it without getting out of bed. 
• The following morning, before you get out of bed, take your temperature via your armpit for 10 minutes while staying as still as possible. 
• Keep records of your temperature for at least three days. (Women should do this during the first two weeks of the menstrual cycle, as their basal temperature may rise during the latter half.)
• Normal basal body temperatures fall between 97.4° F and 97.8° F. If your basal temperature is consistently low, you could be mildly hypothyroid.

If you have one or more adenomas, your doctor will want to keep careful records of when they were first found and how they develop, since not all adenomas produce excess thyroid hormone. In fact, most of these nodules are not malignant, especially if they remain the same size over long intervals.  (Cancerous tissue, by contrast, will undergo noticeable growth.)