Question

The most common cause of hyperthyroidism is:

a. Graves disease.

b. A toxic uninodular goiter.

c. Subacute thyroiditis.

d. A pituitary tumor.

Answer 1

The most common cause of hyperthyroidism is Graves' disease, an autoimmune disorder that stimulates the thyroid to produce excessive amounts of thyroid hormones.

Step-by-step explanation:

The most common cause of hyperthyroidism is Graves' disease. Graves' disease is an autoimmune disorder in which abnormal antibodies stimulate the thyroid to secrete excessive amounts of thyroid hormones. This stimulation overrides the usual feedback mechanism that controls thyroid hormone production, leading to the symptoms of hyperthyroidism.