What are the common symptoms of hypothyroidism?

Hypothyroidism is characterized by an underactive thyroid gland, which leads to a decrease in the levels of thyroid hormones in the body. The common symptoms of this condition often include cold intolerance and weight gain.

Cold intolerance occurs because thyroid hormones play a crucial role in regulating metabolism and body temperature. When hormone levels are low, the body's ability to generate heat diminishes, leading individuals to feel more sensitive to cold environments.

Weight gain is also a typical symptom, as a lack of sufficient thyroid hormones slows down metabolism. This slowdown can lead to an accumulation of calories and fat, contributing to an increase in body weight.

In contrast, the other options describe symptoms associated with hyperthyroidism, where there is an overproduction of thyroid hormones resulting in symptoms like increased energy, weight loss, rapid heartbeat, sweating, increased appetite, and heat intolerance. These symptoms are not characteristic of hypothyroidism, reinforcing why the cold intolerance and weight gain associated with hypothyroidism is the correct answer.