Which among the following describes a patient with hypothyroidism potentially caused by longer-term medication use?

A patient with hypothyroidism typically presents with a range of symptoms related to a decreased metabolic rate due to underactive thyroid function. Weight gain is a classic symptom of this condition. When metabolism slows, the body's ability to convert food into energy diminishes, leading to an increase in body weight despite potentially unchanged eating habits. Medications known to cause hypothyroidism, such as lithium or amiodarone, may result in a gradual onset of these symptoms as they impact thyroid hormone production.

In contrast, increased appetite, heat intolerance, and insomnia are generally associated with hyperthyroidism rather than hypothyroidism. Hyperthyroidism results in an elevated metabolic rate, which can lead to weight loss and increased appetite, as well as symptoms that reflect heightened physiological activity, such as heat intolerance and insomnia. Thus, weight gain stands out as the correct symptom indicative of a patient with hypothyroidism due to medication use.