Which of the following are signs and symptoms of hypothyroidism?

The presence of fatigue, weight gain, and cold intolerance are classic signs and symptoms associated with hypothyroidism. This condition occurs when the thyroid gland does not produce sufficient amounts of thyroid hormones, leading to a slowdown in the body’s metabolism. Fatigue is prevalent due to reduced metabolic activity, which can cause a general sense of tiredness and lethargy. Weight gain often occurs as the body becomes less efficient at using energy and storing calories. Cold intolerance emerges because thyroid hormones play a crucial role in regulating body temperature; a deficiency results in a decreased ability to generate heat, making individuals feel colder than those with normal thyroid function.

Other options present symptoms that are more characteristic of hyperthyroidism, a condition characterized by excess thyroid hormone. Symptoms like weight loss, heat intolerance, rapid heartbeat, sweating, insomnia, increased energy, irritability, and restlessness indicate heightened metabolic activity, which is the opposite of what occurs in hypothyroidism. Hence, the signs and symptoms in the correct answer align specifically with the physiological manifestations of hypothyroidism.