Diagnostic Considerations
If an associated ophthalmopathy is present, the diagnosis of diffuse toxic goiter (Graves disease) is obvious.
Other common causes of hyperthyroidism include various forms of thyroiditis, hyperfunctioning (hot) nodule, multinodular goiter, and iatrogenic (thyroxine and/or triiodothyronine ingestion). Iodine administration, such as drugs or contrast media, may precipitate hyperthyroidism in the presence of underlying nodular thyroid disease. Palpation of the thyroid gland gives useful clinical information in the separation of these entities.
Rare causes include thyroid-stimulating hormone (TSH)-secreting pituitary tumors, ectopic thyroxine production (struma ovarii), human chorionic gonadotropin (HCG) hypersecretion (trophoblastic disease, ectopic secretion), exogenous sources (eg, hamburger thyrotoxicosis), and malingering (thyroxine ingestion). Peripheral resistance to thyroid hormone (receptor defect) may result in a complicated, similar clinical picture.
Anxiety/psychotic state, pheochromocytoma, pregnancy and hyperemesis gravidarum, menopause, carcinoid syndrome, and cocaine and other drug use are possible.
Primary systemic or organ diseases, such as atrial fibrillation, weight loss, or myopathy, require hyperthyroidism to be considered as an underlying cause.
