A patient presents with nervousness, heat intolerance, weight loss, bulging eyes, and stare. Which diagnosis is most likely?

• A. Hashimoto's thyroiditis
• B. Graves' disease
• C. Addison's disease
• D. Cushing's disease

Answer: (B)

The key idea is autoimmune stimulation of the thyroid with eye involvement leading to hyperthyroidism. Nervousness, heat intolerance, and weight loss come from increased thyroid hormone production, raising metabolic rate. Bulging eyes and a persistent stare are classic signs of Graves’ ophthalmopathy, caused by autoimmune inflammation in the orbit. TSH receptor–stimulating antibodies drive the thyroid to produce excess hormone, while the same autoimmune process targets orbital tissues, causing edema and expansion of extraocular muscles with glycosaminoglycan deposition.

Hashimoto's thyroiditis causes hypothyroidism rather than hyperthyroidism and does not typically produce exophthalmos. Addison's disease presents with adrenal insufficiency (fatigue, hypotension, hyperpigmentation), not hyperthyroid symptoms. Cushing's disease involves cortisol excess with features like weight gain and proximal muscle weakness, not exophthalmos.