Graves’ disease occurs when your child’s immune system develops antibodies that attach to the thyroid cells, causing them to produce too much thyroid hormone. This antibody, thyroid-stimulating immunoglobulin (TSI), binds to the thyroid-stimulating hormone (TSH) receptor and causes unregulated production and release of thyroid hormone.

Graves’ disease affects 1 in 10,000 children in the United States and is much less common than Hashimoto's thyroiditis. It is more common in girls than in boys.