Which of the following is a sign of thyrotoxic crisis in Graves' disease?

• A. Fever
• B. Pallor
• C. Bradycardia
• D. Weight gain

Answer: (A)

Thyrotoxic crisis is an extreme, life-threatening escalation of Graves' thyrotoxicosis where metabolism runs at full tilt and heat production skyrockets. The fever comes from this heightened metabolic state and the body’s struggle to dissipate the excess heat. Along with a very high fever, patients often exhibit rapid heart rate, sweating, agitation, and GI symptoms, all reflecting the surge in thyroid hormone effects.

Pallor is not typical because the skin tends to be warm and sweaty rather than pale in this crisis. Weight gain would contradict the catabolic state of thyrotoxicosis, which usually causes weight loss. Bradycardia runs against the expected cardiovascular response; thyroid storm typically produces tachycardia due to sympathetic activation.

So, fever best reflects the severe hypermetabolic and heat-generating nature of a thyrotoxic crisis in Graves' disease.