Answer:
Increases.
Step-by-step explanation:
Hormones may be defined as the chemical messengers of the body that can transmit information and maintains homeostasis. The hormones can directly go into the bloodstream and may release through the special ducts.
Thyroid hormones maintain the biochemical pathway and the overall body metabolism. The levels of the thyroid hormone increases in the winter and decreases in the summer. This is because in winter our body requires more heat and it can be achieved by producing the excess thyroid hormone.
Thus, the answer is increase.