What are the causes of hyperthyroidism?
Graves’ disease is an autoimmune disorder and is the most common cause of hyperthyroidism. The thyroid gland is diffusely enlarged and patients usually complain of eye discomfort or, in extreme cases, bulging eyes. This is most commonly seen among young females and affects multiple family members. A toxic nodule is a single nodule or lump in the thyroid gland that over-produces hormones, causing hyperthyroidism. Unlike Graves’ disease, this is not familial. It is also known as Plummer’s nodule. Toxic multinodular goiter is usually seen in patients more than 50 years old who had long-standing goiters. Unlike Plummer’s nodule, several nodules may hyperfunction in this condition. Acute or subacute thyroiditis presents with an antecedent viral infection with thyroid gland enlargement, later developing symptoms of hyperthyroidism because of leakage of thyroid hormones in the bloodstream. Fortunately, this condition resolves spontaneously, but may later cause hypothyroidism.
