Hypothyroidism

Hypothyroidism refers to an underactive thyroid or low thyroid function, and is an endocrine disorder in which the thyroid gland does not produce enough thyroid hormones.

Causes
Hypothyroidism has a number of different causes, including:
 * Hashimoto's thyroiditis, also known as Hashimoto's disease
 * Congenital hypothyroidism, which is when a person is born with hypothyroidism
 * Thyroid surgery that removes all or part of the thyroid
 * Past radiation treatment of the thyroid
 * Other causes include certain medicines, too much or too little iodine in the diet, or pituitary disease (which is another endocrine disease).