This test measures the amount of three important hormones: Triiodothyronine (T3), Thyroxine (T4), and Thyroid Stimulating Hormone (TSH). These hormones regulate metabolism, energy, and mood. Abnormal levels indicate Hypothyroidism (underactive) or Hyperthyroidism (overactive).
TSH is produced by the pituitary gland to stimulate the thyroid. High TSH usually means your thyroid is underactive (Hypothyroidism), and low TSH means it is overactive (Hyperthyroidism).
Fasting is not strictly required for a Thyroid Profile, but avoiding heavy meals before the test is good practice.