Guide to Thyroid Self-Tests
Home thyroid tests should always be confirmed by
Hi, I'm Dr. Michael Via, with Beth Israel Medical Center, Division of Endocrinology and Metabolism, and I'm here today with About.com to talk about thyroid self-tests.It is estimated that over 10 million Americans have thyroid conditions, of which a significant portion may go undiagnosed for months or even years due to the subtle nature and insidious onset of symptoms.When a thyroid condition is suspected in a patient, a doctor will often use blood tests to check and monitor thyroid function.The most commonly used and most sensitive blood test is a measure of TSH, or thyroid stimulating hormone. This is actually a pituitary hormone released to stimulate the thyroid gland. The brain, which signals the pituitary, is constantly sampling the blood to measure levels of thyroid hormone. If there is not enough thyroid hormone, more TSH is produced, and if there is too much, less TSH is produced. Many population based studies show TSH to be the most sensitive and accurate of thyroid function tests.Just as self-tests are designed to detect pregnancy and fertility, home blood tests are available for the checking thyroid function. These tests include a finger-pricking sterile device that collects a small blood sample and deposits it on a test cassette; after adding a buffer solution, the blood reacts and a reading of TSH levels is given within minutes.Similar tests require the patient to send the test cassette to a lab for analysis.Just as with home pregnancy testing, home thyroid testing should always be confirmed by your doctor.Other thyroid function blood tests measure thyroid hormones directly, which include measurements of T4 and T3, or thyroxine and triiodothyronine, respectively. T3 is the active thyroid hormone, which is produced in only small quatities by the thyroid. T4 is released in much larger amounts and must be converted to T3 by the peripheral tissues.Both hypothyroidism and hyperthyroidism can be diagnosed with this line of testing, and should be treated accordingly.Since currently available thyroid function tests are highly sensitive, they can detect even very mild changes in thyroid function that do not produce symptoms. This grey area, in which thyroid function tests show a very minor abnormality but the patient displays no obvious symptoms is considered as subclinical thyroid disease.Presently, it is controversial whether or not to treat individuals with subclinical hypothyroidism or with subclinical hypothyroidism with subclinical hyperthyroidism.To find out more, go to About.com.