When considering a hyperthyroidism diagnosis, your healthcare provider will start by asking specific questions about your medical history and symptoms. A thorough physical exam will also be performed; if hyperthyroidism is suspected, the exam will likely be followed by blood tests, such as a thyroid-stimulating hormone test or a T3 and T4 test.
How Is Hyperthyroidism Diagnosed?In order to diagnose hyperthyroidism, healthcare providers will begin by asking a number of questions, including questions about possible hyperthyroidism symptoms and signs. They will then perform a thorough physical examination. Finally, they may recommend several tests to confirm the diagnosis and find its cause.
Tests Used to Make a Diagnosis of HyperthyroidismA couple of tests are used to confirm a hyperthyroidism diagnosis. The first is a blood test that looks at thyroid-stimulating hormone (TSH) levels.
Thyroid-Stimulating Hormone Test
The TSH test is usually the first test a healthcare provider performs. This is the most accurate measure of thyroid activity available because TSH can be low even with small increases in thyroid function.
The TSH test is based on the way TSH and thyroid hormone work together. The pituitary gland boosts TSH production when the thyroid is not making enough thyroid hormone; the thyroid normally responds by making more.
When the body has enough thyroid hormone circulating in the blood, TSH output drops. In people who produce too much thyroid hormone, the pituitary shuts down TSH production, leading to low or even undetectable levels in the blood.
Generally, a TSH reading below normal indicates hyperthyroidism, and a reading above normal means a person has hypothyroidism.