Hypothyroidism is a result of the body's thyroid gland secreting an insufficient amount of thyroid hormone. While this illness can be debilitating and potentially can lead to even more serious health complications, it can also be a difficult disease for doctors to properly and accurately diagnose. However, a number of diagnostic tests can be used to detect the disease so you can obtain the medical treatment you may need.
Thyroid Stimulating Hormone (TSH) Test
Thyroid Stimulating Hormone (TSH) is produced by the body's pituitary gland. In instances of hypothyroidism, the amount of TSH produced will be higher than normal, since the pituitary gland is producing elevated levels of TSH in response to the thyroid gland's inefficiency. TSH tests are not always completely accurate and, because of this, they are usually combined with additional types of blood testing.
T4 Blood Test
The T4 test measures the amount of thyroxine (a particular thyroid hormone produced by the thyroid gland) present in the subject's blood. Low levels of the hormone may indicate the thyroid gland is not making enough of the hormone and may point to a potential hypothyroid issue. As thyroxine represents about four-fifths of the thyroid hormone produced by the gland, this particular assay is the most often used thyroid-related diagnostic test.
T3 Blood Test
After thyroxine (T4), the highest concentration of thyroid hormone in the blood is triiodothyronine, or T3. Approximately one-fifth of the hormones produced by the thyroid gland belong to this group. Though it is produced in lower concentrations, the T3 hormone is an important indicator to test for as triiodothyronine has a greater effect than T4 on the body's use of energy.
Iodine Uptake Scan
Iodine uptake scans are employed to confirm a diagnosis of hypothyroidism. People suffering from hypothyroidism generally take up too little iodine via their thyroid gland, so this test can be useful for confirming the condition. A small amount of radioactive iodine is given to a patient as part of the procedure, and the amount of thyroid uptake is subsequently measured. As with other tests, this procedure is best interpreted when used in conjunction with additional blood testing and with a separate thyroid scan.
Thyroid Scan
A scan of the thyroid is usually performed at the same time as the iodine uptake scan. The thyroid scan is performed by giving the patient a radioisotope and scanning the thyroid gland as it concentrates the administered isotope. Areas of decreased activity detected in the gland, referred to as "cold spots" on this scan, may be an indication that area of the thyroid is underactive.
