Thyroid replacement can cause symptoms of hyperthyroidism, including which of the following?

• A. Diarrhea, weight loss, palpitations, sweating, heat intolerance
• B. Weight gain, constipation, fatigue, cold intolerance
• C. Headache, dizziness, blurred vision
• D. Nausea, vomiting, abdominal pain

Answer: (A)

When thyroid replacement is taken in excess, it raises the body's metabolic rate and amplifies sympathetic nervous system effects, producing hyperthyroid-like symptoms. Diarrhea from faster gut motility, weight loss despite normal or increased appetite, palpitations from a faster heart rate, sweating, and heat intolerance all reflect this increased metabolism and heat production. This combination directly mirrors having too much thyroid hormone in circulation, which is why that option is the best fit.

The other symptom clusters align more with low thyroid function or non-specific issues: weight gain with constipation and cold intolerance suggests hypothyroidism, while headache/dizziness/blurred vision or nausea/vomiting/abdominal pain aren’t classic hyperthyroid presentations.