Hyperthyroidism can also be caused by thyroiditis, an inflammation of the thyroid gland that often disappears in a few weeks and may be caused by an infection. Toxic nodular goiter also can occur when part of the thyroid gland enlarges and produces too much thyroid hormone. Many patients with hyperthyroidism are in their 20s or 30s, but it occurs in the elderly as well. In some patients, symptoms clearly indicate hyperthyroidism. In others, symptoms are not so obvious.
Problems can occur in many parts of the body.
Your heart may pound or beat very fast. You may feel nervous, anxious, irritable, or forgetful. You might fidget or tremble. Elderly people may feel listless or depressed. Without changing your eating habits, you may be losing weight.