Hyperthyroidism. Causes, clinical features, and diagnosis

The usual patient with hyperthyroidism has Graves' disease: If serum levels of thyroid hormone are clearly elevated, the presence of infiltrative ophthalmopathy or pretibial myxedema is probably sufficient for establishing the diagnosis. However, if the ancillary findings of Graves' are not present, the radioactive iodine uptake should be determined to rule out other possible etiologies of hyperthyroidism. Signs of hyperthyroidism may be subtle or misleading, particularly in the elderly; the well-informed clinician keeps the diagnosis in mind, and if the initial thyroid hormone tests are not definitive, employs additional tests that are cost-effective in the individual clinical situation.