How is thyroiditis diagnosed?
Tests for thyroiditis may include:
- Thyroid function tests measure the amounts of hormones (thyroid-stimulating hormone or TSH, T3 and T4) in the blood. TSH comes from the pituitary gland and stimulates the thyroid gland to produce T4 and T3. The thyroid gland produces the hormones T4 and T3 that exert the action of thyroid hormone in the body. T3 and T4 are called the thyroid hormones.
- Thyroid antibody tests measure thyroid antibodies that includes antithyroid (microsomal) antibodies (TPO) or thyroid receptor stimulating antibodies (TRAb).
- Erythrocyte sedimentation rate (ESR or sed rate) indicates inflammation by measuring how fast red blood cells fall. The ESR is high in sub-acute thyroiditis.
- Ultrasound (US), sonogram of the thyroid, is used very frequently to evaluate the anatomy of the thyroid gland. It can show a nodule (a growth) in the thyroid gland, change in blood flow (Doppler mode) and echo texture (intensity/density) of the gland.
- Radioactive iodine uptake (RAIU) measures how much radioactive iodine is absorbed by the thyroid gland. The amount is always low in the thyrotoxic phase of thyroiditis.