Guide To Common Blood Tests

Thyroid Panel

Also known as a thyroid function test, a thyroid panel helps doctors understand how well a patient's thyroid is manufacturing and responding to particular hormones. The thyroid is a gland in the neck involved in regulating metabolism, mood, and energy. This test is often ordered if a patient is experiencing symptoms that could indicate a thyroid issue. These symptoms include weight gain, fatigue, mood swings, and feeling cold. Levels of triiodothyronine (T3), thyroxine (T4), T3 resin uptake (RU), and thyroid-stimulating hormone (TSH) are all measured as part of a thyroid panel. The first two regulate body temperature, heart rate, metabolism, and growth. Thyroid-stimulating hormone controls the quantities of hormones released by the thyroid. T3 resin uptake is a measure of how well a hormone known as thyroxine-binding globulin is performing.

Thyroid panel results outside of the normal range could indicate a patient has a thyroid growth disorder or low protein. They may also have abnormal levels of testosterone or estrogen. Patients who have abnormal results on a thyroid test are typically referred for a thyroid uptake test and an ultrasound of the thyroid gland. Issues involving an overactive or underactive thyroid can normally be treated with medication.