When Graves’ disease is suspected based on a person’s symptoms (particularly skin and eye symptoms and an enlarged thyroid gland), a doctor will order testing to evaluate thyroid gland function. Blood tests will be performed to analyze levels of thyroid hormones and check for the presence of particular autoantibodies. Diagnosis can be confirmed through radioactive iodine uptake testing. The thyroid gland absorbs iodine to make thyroid hormones, and in people with Graves’ disease, overproduction of thyroid hormones increases iodine uptake by the thyroid gland, which can be measured with a thyroid scan. Doctors will also use the thyroid scan to analyze the pattern of iodine uptake, which can help to distinguish Graves’ disease from other thyroid disorders.[1]