Common signs. If someone has hyperthyroidism, they will have some notable symptoms. Symptoms include mood swings, feeling weak or tired, feeling irritable, anxious, or nervous, sensitivity to heat, enlarged thyroid, losing weight, palpitations of the heart, or irregular heartbeat, sleep issues, shaking in the hands and fingers, and increased bowel movements. It is important to note that if a person has these symptoms, they need to see their doctor as soon as possible. The quicker treatment begins for this condition the better. There are treatment options that will help to alleviate all the symptoms of this disorder.