Hyperthyroidism refers to overactivity of the thyroid gland resulting in excessive secretion of thyroid hormones throughout the body. Some common causes include Graves' disease, toxic adenomas, and thyroiditis. Symptoms include nervousness, palpitations, heat intolerance, tremor, and weight loss. Diagnosis involves tests of thyroid and pituitary hormones. Treatment options are radioactive iodine to destroy the thyroid gland, anti-thyroid medications, beta-blockers to control symptoms, or surgery to remove part or all of the thyroid. Nursing care focuses on managing nutrition, activity tolerance, risk of injury from eye involvement, and hyperthermia due to the increased metabolic rate.