The main secretion of the thyroid gland is thyroid hormone, which is important for the normal development of the human body, and can effectively regulate the energy metabolism and nervous system development in the body. Excessive secretion of hormones by the thyroid gland can also cause symptoms such as sympathetic nerve excitation, heart rate disorder, palpitations, and agitation. Too little hormone secretion by the thyroid gland can lead to symptoms such as drowsiness, lack of concentration, memory loss, and fatigue. Whether the thyroid gland secretes too much or too little hormone, it has adverse effects on the human body. Maintaining normal thyroid hormone secretion is important for human growth and development. If you find that the thyroid gland secretes hormones abnormally, you need to go to the hospital in time for the examination of thyroid secretion indexes, and according to the results of the test to find the cause of the disease, and timely treatment to avoid the development of disease, which will bring a lot of adverse effects to the body.