Graves’ disease can be difficult to diagnosis at first. Aside from ophthalmopathy, most of the symptoms of Graves’ disease are shared with other conditions.
Thyroid-stimulating hormone (TSH) stimulates the thyroid gland to release thyroxine (T4) and triiodothyronine (T3); a doctor may take a blood sample to measure levels of these hormones.
Abnormally high levels of T3 and T4, and a very low level of TSH, are good indications of Graves’ disease.
Another test for Graves’ disease is called radioactive iodine uptake. The patient consumes a small quantity of radioactive iodine by liquid or capsule. Once swallowed, the iodine collects in the thyroid.
The doctor will then perform several scans using a radioactive tracer, the first is usually done 4-6 hours after the iodine has been taken. Following this, a second scan is usually taken 24 hours later.