Which of the following best defines hypothyroidism?

Hypothyroidism is best defined as insufficient thyroid hormone production. In this condition, the thyroid gland does not produce enough hormones, specifically thyroxine (T4) and triiodothyronine (T3), which are essential for regulating metabolism, energy levels, and overall bodily functions. The lack of these hormones can lead to various symptoms, including fatigue, weight gain, cold intolerance, and depression, among others. Understanding this definition is crucial, as it helps to identify the underlying issues that can arise from hormone deficiencies and highlights the importance of thyroid function in maintaining health.