Hyperthyroidism is a condition where the thyroid gland produces too much thyroid hormone. This hormone helps regulate many body functions, including metabolism, energy levels, and heart rate. When there is an excess, it can lead to symptoms like weight loss, increased heart rate, anxiety, and sweating. People with hyperthyroidism may feel restless and have difficulty sleeping. One common cause of hyperthyroidism is an autoimmune disorder called Graves' disease. This condition causes the immune system to mistakenly attack the thyroid, leading to overproduction of hormones. Treatment options include medications, radioactive iodine, or sometimes surgery to remove part of the thyroid gland.