Final answer:
Signs of Synthroid overdose in a child with hypothyroidism include tachycardia, diarrhea, sweating, and irritability, which are indicative of hyperthyroidism.
Step-by-step explanation:
The home health nurse monitoring an 8-month-old child with hypothyroidism taking Synthroid would recognize the following symptoms as signs of overdose: tachycardia (a rapid heart rate), diarrhea, sweating, and irritability. These are symptoms that could indicate that the patient is experiencing effects of excess thyroid hormone, characteristic of hyperthyroidism. In contrast to the symptoms of hypothyroidism, which include fatigue, weight gain, and coldness, hyperthyroidism symptoms often involve an increased metabolic rate and overactivity of the thyroid gland