How Are Thyroid Disorders Diagnosed?

You may not spend much time thinking about whether your thyroid gland is functioning well, but it's more important than you would probably guess. This butterfly-shaped organ wraps around your windpipe and sits just beneath the Adam’s apple.

Despite its small size, the thyroid gland contributes in large ways to the overall quality of your life. It plays a key role in the body’s endocrine system, which regulates metabolism, growth and development, reproduction, sleep and mood.

How Are Thyroid Disorders Diagnosed?

Your doctor will perform a physical examination and take your medical history. If thyroid disease is suspected, your physician will order a blood test to measure thyroid-stimulating hormone (TSH). Low levels of TSH can be the first indication of a thyroid disorder. 

Another blood test measures a hormone called T4, also produced by the thyroid. A third blood test is called the anti-thyroid microsomal antibody test. This measures the amount of anti-thyroid peroxidase (anti-TPO) antibodies in the blood stream. Large amounts of antibodies, which are produced by the immune system, could indicate that some thyroid damage has already occurred.

If you have an abnormally high level of the hormone TSH, then you might have an under-active thyroid gland, a condition called hypothyroidism. Low levels of TSH is an indicator of hyperthyroidism.