What Causes Hyperthyroidism?
- An autoimmune disorder, such as Graves’ disease (this is the most common cause of hyperthyroidism)
- One or more thyroid nodules (growth/s within the thyroid gland) that make excess thyroid hormone
- Inflammation of the thyroid gland, such as thyroiditis
- Over-treatment of an underactive thyroid (if too much thyroid hormone is taken for replacement)
- Genetic conditions and rare ovarian tumors
- A tumor in the pituitary gland (a small gland in the brain that controls other glands in the body) that make an excess of a hormone called thyroid stimulating hormone (TSH) that pushes the thyroid gland to make too much thyroid hormone
Thyroid storm is a rare, but very serious type of hyperthyroidism in which thyroid hormone levels are extremely high.