As a result, the body has too much thyroid hormone. The thyroid gland is key to maintaining normal metabolism. Metabolism is the rate at which the body's cells do their work. Metabolism regulates your heart rate, the amount of calories you burn when you are resting, your energy level, and other bodily functions. When thyroid function becomes abnormal, the effects on your body can be dramatic.
Many people feel nervous or out of control of their emotions.
Some feel muscle weakness, especially in the thigh muscles when going up stairs. A few people notice a swelling in their neck because of an enlarged thyroid. An enlarged thyroid gland is called a goiter. About half of all people with Graves' disease develop eye symptoms. These symptoms include eyes that protrude more than usual from the sockets and eyelids that do not completely close over the eye.