What is hypothyroidism?

Dr. Jeanne Morrison, PhD
Family Practitioner

Hypothyroidism results when the thyroid gland produces too little thyroid hormone. The thyroid is a gland located at the base of the neck below the voice box. It is about two inches long and is shaped like a butterfly. Its purpose is to produce thyroid hormones, which regulate the body's metabolism. Hypothyroidism can slow down several bodily functions.

Marjorie Nolan Cohn
Nutrition & Dietetics

Hypothyroidism (underactive thyroid) is a condition in which your thyroid gland doesn't produce enough of the thyroid hormone. Hypothyroidism can also be secondary if it is caused by a lack of thyroid hormone secretion due to inadequate secretion of thyrotropin (thyroid-stimulating hormone [TSH]) from the pituitary gland or thyrotropin-releasing hormone (TRH) from the hypothalamus (secondary or tertiary hypothyroidism). Whether it’s primary or secondary, the symptoms are the same.

Hypothyroidism is a thyroid problem in which the thyroid is underactive or non-active. It is more often seen in women than men. In general, hypothyroidism can be diagnosed by a thorough history and blood tests. Hypothyroidism is most commonly caused by an underlying thyroid disease (primary hypothyroidism) instead of a problem with TSH production (secondary hypothyroidism). The most common causes of primary hypothyroidism are autoimmune thyroiditis (Hashimoto's thyroiditis or lymphocytic thyroiditis), surgical removal of the thyroid (thyroidectomy), radioactive iodine treatment, certain medications, and exposure of the neck to significant radiation.
Hypothyroidism is a condition in which the thyroid gland does not produce enough of certain hormones.  Symptoms may vary and may increase in severity if left untreated.

Continue Learning about Hypothyroidism

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.