Hyperthyroidism and hyperthyroidism symptoms occur when the thyroid gland produces too many thyroid hormones. This small butterfly-shaped gland sits in front of the trachea (windpipe) in the neck. It produces two main thyroid hormones, triiodothyronine (T3) and thyroxine (T4). These hormones regulate your metabolism, body temperature, and heart rate. Unfortunately, too many of these hormones…