Which of the following is a common symptom of hypothyroidism?

Muscle weakness is a common symptom of hypothyroidism due to the decreased levels of thyroid hormones, which play a crucial role in regulating metabolism and energy levels within the body. When thyroid hormone production is insufficient, it can lead to a slowdown in various metabolic processes, affecting muscle performance and energy utilization. As a result, individuals with hypothyroidism may experience fatigue, reduced strength, and muscle weakness, which can significantly impact their daily activities and overall physical function.

The other symptoms listed do not align with hypothyroidism. Increased appetite and weight loss are more commonly associated with conditions like hyperthyroidism, where there is an excess of thyroid hormones. High blood pressure is not typically a direct symptom of hypothyroidism; rather, it can be influenced by other underlying factors not directly related to thyroid hormone levels. Therefore, muscle weakness accurately represents a hallmark symptom of hypothyroidism, illustrating the condition's impact on physical strength and energy.