Graves' disease, also known as
toxic diffuse goiter, is an
autoimmune disease that affects the
thyroid. It frequently results in and is the most common cause of
hyperthyroidism. It also often results in an
enlarged thyroid. Signs and symptoms of hyperthyroidism may include irritability, muscle weakness, sleeping problems, a
fast heartbeat, poor tolerance of heat,
diarrhea, and weight loss. Other symptoms may include thickening of the skin on the shins, known as
pretibial myxedema, and
eye problems such as bulging, a condition known as
Graves' ophthalmopathy. About 25% to 80% of people with the condition develop eye problems.