Hypothyroidism

Hypothyroidism is a condition in which the thyroid gland or its regulatory system produces too little thyroid hormone for the body’s needs. It slows processes that depend on thyroid hormone.

Thyroid hormone: Thyroxine and triiodothyronine are hormones that regulate metabolism, growth, and development. Their deficiency produces the physiological changes that define hypothyroidism.
Thyroid gland: An endocrine gland in the neck that produces hormones regulating metabolism and development. It is the main source of the hormones deficient in primary hypothyroidism.
Thyroid function tests: Blood tests, especially TSH and free T4, used to assess thyroid function. Their patterns help confirm hypothyroidism and locate the level of dysfunction.
Hyperthyroidism: A condition in which thyroid hormone production or availability exceeds the body's needs. It generally accelerates metabolism, contrasting with the slowing associated with hypothyroidism.
Hypothyroidism in pregnancy: Thyroid hormone deficiency occurring before or during pregnancy. Maternal thyroid status matters for pregnancy health and fetal development.
Thyroid-stimulating hormone: A pituitary hormone that stimulates the thyroid gland to produce thyroid hormones. Its level usually rises when the thyroid cannot meet the body's hormone demand.
Thyroxine: Thyroxine, or T4, is the principal hormone secreted by the thyroid gland and a precursor to T3. Blood tests commonly measure T4 to assess the hormone shortfall.
Levothyroxine: A synthetic form of thyroxine used to replace thyroid hormone. It is the standard long-term treatment for most forms of hypothyroidism.
Euthyroid state: A state in which thyroid hormone function is within the body's normal range. Symptoms alone cannot establish deficiency when thyroid function remains normal.
Cretinism: An outdated term for severe developmental impairment caused by untreated congenital thyroid hormone deficiency. It illustrates the lasting harm prevented by newborn screening and early treatment.

Linked from 24 pages