Typical systemic effects of hyperthyroidism include which of the following?

• A. Increased basal metabolic rate, tachycardia, weight loss, heat intolerance, tremor.
• B. Decreased basal metabolic rate and bradycardia
• C. Weight gain and cold intolerance
• D. Normal metabolic rate with fatigue.

Answer: (A)

Hyperthyroidism boosts the body's metabolic activity and sympathetic effects. Excess thyroid hormones (T3/T4) speed up nearly all body systems, so the basal metabolic rate rises, and tissues demand more energy. That higher metabolic demand pushes the heart to work harder, producing tachycardia. The accelerated metabolism also leads to weight loss despite normal or increased appetite. Heat production goes up, so people commonly experience heat intolerance. The nervous system becomes more excitable, often causing a tremor. Altogether, this combination—higher basal metabolic rate, rapid heart rate, weight loss, heat intolerance, and tremor—fits hyperthyroidism well. Opposite patterns, like decreased metabolic rate with bradycardia or weight gain with cold intolerance, align with hypothyroidism or non-thyroid conditions, not hyperthyroidism.