Which symptom is a classic manifestation of hypothyroidism?

Cold intolerance and weight gain are indeed classic manifestations of hypothyroidism. In this condition, the thyroid gland does not produce enough thyroid hormones, leading to a slower metabolic rate. This slow metabolism can result in an increased sensitivity to cold temperatures, as the body struggles to generate adequate heat.

Weight gain is another characteristic symptom, as a reduced metabolic rate means that energy expenditure is lower, even if caloric intake remains the same. Furthermore, hypothyroidism often leads to fluid retention, which can contribute to weight gain as well. Other symptoms may include fatigue, dry skin, hair loss, and constipation, but cold intolerance and weight gain are particularly emblematic of the hormonal decrease associated with an underactive thyroid.