What does hyperthyroidism mean?
Hyperthyroidism is a medical condition in which the thyroid gland produces too much thyroid hormone. The resulting increase in metabolic activity can lead to weight loss, rapid or irregular heartbeat, tremor, sweating, heat intolerance, fatigue, anxiety, and difficulty sleeping. The condition may be caused by Graves’ disease, thyroiditis, an overactive thyroid nodule, or certain medications, and it is diagnosed through symptoms, physical examination, blood tests, and sometimes thyroid imaging or scans. Hyperthyroidism is different from hypothyroidism: in hyperthyroidism, metabolism is generally increased, while in hypothyroidism it is slowed. Although the related term thyrotoxicosis is often used alongside it, the terms are not completely interchangeable in every clinical context. The word is useful because it names the precise condition behind symptoms commonly described simply as an overactive thyroid.
nounA medical condition in which the thyroid gland produces excessive amounts of thyroid hormone, causing the body’s metabolism to speed up. It may result from an overactive thyroid gland, such as Graves’ disease or thyroiditis, and can cause symptoms including weight loss, rapid heartbeat, tremor, heat intolerance, and anxiety.
- The medical condition of having an overactive thyroid gland that produces excess thyroid hormone.
"Her symptoms of weight loss, palpitations, and difficulty sleeping were eventually diagnosed as hyperthyroidism."
"A blood test confirmed that the patient had hyperthyroidism."
"The doctor explained that untreated hyperthyroidism could affect her heart as well as her bones."
The plural is rarely used because the condition is normally discussed in the singular or collectively for a group of patients.
"The clinic specializes in hyperthyroidisms that result from autoimmune thyroid disease."
Hyperthyroidism can make a person lose weight despite eating more, because an overactive thyroid turns the body’s metabolism up.
Reviewed by Deb Chak, Editor. AI-assisted content curated by RJS Tech Solutions LLP.
Where does hyperthyroidism come from?
The word combines the prefix hyper-, meaning “over” or “excessive,” with thyroid, from Greek thyroidē, meaning “shield-shaped,” and the suffix -ism, used to form nouns denoting a condition. The component thyroid ultimately refers to the cartilage protecting the throat, because the thyroid gland was thought to resemble a shield. The compound hyperthyroidism developed in the modern medical period as a term for the clinical condition associated with excessive thyroid activity.
How hyperthyroidism is actually used
This is a formal medical term. In general contexts, “overactive thyroid” is a more accessible expression, while “thyrotoxicosis” is closely related but is not always used as an exact synonym. Diagnosis and treatment require medical evaluation.
Easily confused with hyperthyroidism
Hyperthyroidism involves excessive thyroid hormone and an accelerated metabolism, whereas hypothyroidism involves too little thyroid hormone and a slowed metabolism.
Thyrotoxicosis describes the clinical state caused by excess thyroid hormone, while hyperthyroidism refers more specifically to excessive thyroid hormone production, although the terms are often used interchangeably in medical practice.