hyperthyroidism
Meaning of hyperthyroidism: Hyperthyroidism speeds up the body's metabolism through excess thyroid hormone, most often caused by Graves disease, an autoimmune condition affecting the thyroid gland.
Definition of hyperthyroidism
Hyperthyroidism is a condition in which the thyroid gland produces and releases more thyroid hormone than the body needs. Because thyroid hormone helps regulate the rate of metabolism throughout the body, an excess speeds up many bodily processes.
Common effects of hyperthyroidism include unintended weight loss despite a normal or increased appetite, a rapid or irregular heartbeat, nervousness, tremor, heat intolerance, and diarrhea, and the thyroid gland itself may become visibly enlarged, a change called a goiter.
Graves disease, an autoimmune condition in which the immune system stimulates the thyroid gland to overproduce hormone, is the most common cause of hyperthyroidism, though other causes exist, including nodules within the thyroid that produce hormone independently of the body's normal regulation. Hyperthyroidism is the opposite of hypothyroidism, in which the thyroid produces too little hormone.
How hyperthyroidism is built
- hyper- Prefix · Greek above normal, excessive
- thyr/o, thyroid/o Combining form · Greek thyroid gland
- -ism Suffix · Greek condition, state, process
A medical term is read from its ending backwards: the suffix first, then the prefix, then the root. See all 223 word parts.
Also known as
Used in a sentence
Blood testing confirmed hyperthyroidism after the patient reported weight loss and a rapid heartbeat.
Good to know
Hyperthyroidism and hypothyroidism produce largely opposite effects on metabolism, so distinguishing between the two, generally through blood testing of thyroid hormone levels, guides how the underlying condition is understood.
Word origin
Where “hyperthyroidism” comes from
Formed from Greek hyper-, meaning over or above, and thyroid, from thyreoeides, meaning shield shaped, a term originally describing nearby cartilage before being applied to the gland itself.