A patient with hyperthyroidism is likely to experience which of the following?

In hyperthyroidism, there is an overproduction of thyroid hormones, primarily thyroxine (T4) and triiodothyronine (T3). These hormones play a critical role in regulating the body's metabolism, which refers to the chemical processes that occur within the body to maintain life, including how the body uses energy.

When hyperthyroidism is present, the elevated levels of these hormones lead to an increased metabolic rate. This means the body is undergoing processes such as energy expenditure and heat production at a much higher rate than normal. As a result, patients often experience symptoms such as increased appetite, weight loss despite increased food intake, elevated heart rate, and excessive sweating. The metabolism-driven increase in energy expenditure can contribute to the lean appearance and other metabolic symptoms associated with hyperthyroidism.

In summary, the correct choice reflects the physiological changes that occur in a patient with hyperthyroidism due to excess thyroid hormones, demonstrating clearly why increased metabolism is a hallmark of this condition.