What condition is a 30-year-old woman likely suffering from if she presents with fatigue, weight gain, and bradycardia?

The symptoms described—fatigue, weight gain, and bradycardia—are consistent with hypothyroidism. In this condition, the thyroid gland does not produce enough thyroid hormones, leading to a slower metabolic rate, which can manifest as fatigue and weight gain. Bradycardia, or a slower than normal heart rate, is also a common finding in individuals with hypothyroidism due to decreased sympathetic nervous system activity and a reduced metabolic rate.

The other conditions either do not typically present with these specific symptoms or present with a different symptom profile. For example, hyperparathyroidism is characterized by elevated calcium levels, which can lead to symptoms like kidney stones, abdominal pain, and changes in mood or cognition, rather than fatigue and weight gain. Hyperthyroidism typically presents with weight loss, increased heart rate (tachycardia), and anxiety due to excess thyroid hormone production, which is opposite to the symptoms of hypothyroidism. Hypoparathyroidism usually causes symptoms related to low calcium levels, such as muscle cramps, tingling, and seizures, rather than the fatigue and weight gain seen in hypothyroidism.

Thus, the combination of fatigue, weight gain, and bradycardia strongly points to hypothyroidism as the likely