There are various manifestations of hyperthyroidism. If you experience any of the following symptoms, it is important to go to a regular hospital for further examination in order to detect hyperthyroidism at an early stage and deal with it accordingly. Some common symptoms may include one or more of the following: unexplained irritability and anxiety. Unexplained dramatic weight loss. Sudden increase in the amount of food you eat. Special fear of heat, excessive sweating, irritability. Unexplained panic attacks and hand tremors. Hyperactive gastrointestinal function, with a marked increase in the number of bowel movements. Women may have menstrual disorders, reduced menstrual flow, or even amenorrhea.