Hyperthyroidism is when the thyroid gland makes and secretes very high levels of thyroid hormones. This is caused by abnormal changes or tumors in the gland. These abnormalities are usually benign and can be treated successfully. A small percentage of cases (1-3%) are more complicated to treat and generally have a poorer long-term prognosis.

For further information on symptoms, diagnosis and treatment for hyperthyroidism click here