How is Graves' disease diagnosed?

The steps that may be taken to confirm a suspected diagnosis of Graves' disease may depend in part on a given doctor's familiarity with the disorder. In many situations, a doctor who has encountered and treated a range of different patients with Graves' disease may be able to make a diagnosis after taking a history and performing a careful physical examination. In a typical situation, a patient might be referred to such a doctor after blood tests performed to evaluate concerning symptoms revealed the presence of thyrotoxicosis. After reviewing the blood test results, the doctor would take a history, focusing on questions that may provide clues to the duration and severity of symptoms caused by thyrotoxicosis. Emphasis might be placed on questions related to irritation of the eyes or changes in vision that might reflect underlying thyroid eye disease. The doctor would then perform a careful physical examination that would focus on specific findings. In examining the thyroid gland, the doctor would try to determine whether there was enlargement of the thyroid gland, a palpable pyramidal lobe, a thrill, or a bruit that might be consistent with Graves' disease. In examining the eyes, the doctor would try to determine whether there was any evidence of chemosis, proptosis, or abnormal movement of the eyes that might be consistent with thyroid eye disease. In examining the skin, the doctor would look for evidence of findings consistent with pretibial myxedema. An overall assessment of the clues provided by the history and findings identified on physical examination might enable the doctor to confidently make a diagnosis of Graves' disease. This type of diagnosis, based on evidence derived from a history and physical examination, is known as a clinical diagnosis.

In other situations, it may be difficult for even the most experienced doctor to establish a purely clinical diagnosis of Graves' disease. A definitive diagnosis may depend on the results of radiographic studies. In a typical situation, a thyroid uptake study and thyroid scan may be performed to evaluate the function of a patient's thyroid gland. A thyroid uptake study may help to determine whether a patient's thyrotoxicosis represents hyperthyroidism. In most patients with Graves' disease, a thyroid uptake study will demonstrate increased uptake of tracer at every interval. A simultaneous thyroid scan may help to provide images of the distribution of the increased uptake of tracer. In most patients with Graves' disease, thyroid scan images demonstrate enlargement of the thyroid gland with increased uptake of tracer in both of the lobes.