What is a classic sign of Graves' disease?

• A. Exophthalmos (eye bulging) and diffuse goiter; often with pretibial myxedema
• B. Weight gain and cold intolerance
• C. Proximal muscle weakness
• D. Hypocalcemia and tetany

Answer: (A)

Graves' disease is an autoimmune hyperthyroidism, and the most telling sign is involvement of the eyes together with thyroid enlargement. The classic presentation is exophthalmos, or eye bulging, accompanied by a diffusely enlarged thyroid (diffuse goiter). Sometimes pretibial myxedema appears as well. The eye changes arise from autoimmune inflammation and accumulation of tissues around the orbit, which leads to edema and protrusion of the eyeballs, while the thyroid enlarges due to stimulation by TSH receptor antibodies. This combination of eye findings and a diffusely enlarged thyroid makes Graves' disease distinctive. Signs like weight gain and cold intolerance point to hypothyroidism, not Graves; proximal muscle weakness can occur with thyrotoxicosis but isn’t the hallmark; and hypocalcemia with tetany relates to parathyroid issues rather than Graves.