Which condition is associated with low levels of thyroid hormones?

Low levels of thyroid hormones are specifically associated with hypothyroidism. This condition occurs when the thyroid gland does not produce enough thyroid hormones, leading to a variety of symptoms such as fatigue, weight gain, cold intolerance, and depression. Thyroid hormones are crucial for regulating metabolism, energy production, and overall bodily functions.

In contrast, the other conditions listed are not characterized by low thyroid hormone levels. Hyperthyroidism, for instance, is a condition where the thyroid gland produces excessive hormones, resulting in symptoms such as weight loss, increased heart rate, and anxiety. Hypocalcemia refers to low levels of calcium in the blood and is not directly related to thyroid hormones. Diabetes mellitus is a metabolic disorder primarily related to insulin and blood sugar regulation, which also does not involve thyroid hormone levels. Thus, hypothyroidism is the clear condition associated with low thyroid hormone levels.