A nurse is assessing a client who has Graves' disease and is taking methimazole. Which of the following findings indicates the client needs a lower dose of the medication?

The correct answer is D: Bradycardia. Methimazole is used to treat hyperthyroidism, including Graves' disease, by reducing thyroid hormone production. Bradycardia, or a slow heart rate, can indicate hypothyroidism, which may occur as a side effect of methimazole overdose. Lowering the dose of methimazole can help prevent this adverse effect. Exophthalmos, weight loss, and diaphoresis are common symptoms of hyperthyroidism, which methimazole is intended to treat, so they do not indicate a need for a lower dose of the medication.