Thyroid disease cannot be diagnosed by:
1. A swelling in the neck.
2. Body temperature – while low body temperature is often an indicator of hypothyroidism, it also occurs in healthy people.
3. Slowed reflexes – this may indicate any number of diagnoses.
There are several tests used to evaluate thyroid function. Most of them involve drawing a blood sample.
TSH Test
One of the ways to evaluate thyroid function is measuring TSH (a blood test). Normal levels have changed lately. The older normal levels were 0.5 to 5. According to American Association of Clinical Endocrinologists the newer normal levels is 0.3 to 3 (and they will consider treatment of those who fall outside of this range.).
* An elevated TSH level may indicate hypothyroidism.
* While a low TSH level may indicate hyperthyroidism.
Free T4 Test
* An elevated level may indicate hyperthyroidism.
* While a low level may indicate hypothyroidism.
T 3 Test
* An elevated level may indicate hyperthyroidism.
* While a low level may indicate hypothyroidism. However, in severe hypothyroidism the T3 may be normal with a high TSH.
Special Note: No single blood test can be used to diagnosis thyroid disease with 100% accuracy. It is a combination of the blood test that actually diagnoses thyroid disease.
Radioactive Iodine Uptake Test (not a blood test)
You swallow a small amount of iodine (which is radioactive). This radioactive material is traced as it is taken up by the thyroid. A very high uptake of this material by the thyroid indicates that is hyperactive (hyperthyroidism). While a low uptake indicates hypoactivity (hypothyroidism).