At a Glance Patients with central hypothyroidism have either a failure of the anterior pituitary to secrete TSH (also known as secondary hypothyroidism), failure of the hypothalamus to secrete thyroid releasing hormone (TRH) known as tertiary hypothyroidism, or, in some rare cases, a TSH deficiency with no other findings of pituitary or hypothalamus abnormality. The…
At a Glance The thyroid gland produces, secrets, and stores two related hormones, thyroxine (T4) and triiodothyronine (T3), which play a critical role in thermogenic and metabolic homeostasis. T4 and T3 are normally synthesized and released in response to a combined hypothalamic pituitary signal mediated by thyroid stimulating hormone (TSH) from the anterior pituitary and…
At a Glance The thyroid gland produces two related hormones, thyroxine (T4) and triiodothyronine (T3), which play a critical role in thermogenic and metabolic homeostasis. T4 and T3 are normally synthesized and released in response to a combined hypothalamic pituitary signal mediated by thyroid stimulating hormone (TSH) from the anterior pituitary and thyrotropin releasing hormone…
At a Glance Postpartum thyroid dysfunction, also known as postpartum thyroiditis (PPT), affects approximately 4-10% of postpartum women. PPT often occurs in stages, with thyrotoxicosis appearing first, followed by hypothyroidism. Not all women experience both stages of PPT. Approximately one-third of women with postpartum thyroid dysfunction exhibit both stages of the disease, whereas one-third of…
At a Glance The thyroid gland produces 2 related hormones, thyroxine (T4) and triiodothyronine (T3). T3 and T4 are normally synthesized and released in response to a combined hypothalamic pituitary signal mediated by thyroid stimulating hormone (TSH) from the anterior pituitary and thyrotropin releasing hormone from the hypothalamus. There is a negative feedback on TSH…
At a Glance The thyroid gland produces two related hormones, thyroxine (T4) and triiodothyronine (T3), which play a critical role in thermogenic and metabolic homeostasis. T4 and T3 are normally synthesized and released in response to a combined hypothalamic pituitary signal mediated by thyroid stimulating hormone (TSH) from the anterior pituitary and thyrotropin releasing hormone…
At a Glance The thyroid gland produces two related hormones, thyroxine (T4) and triiodothyronine (T3), which play a critical role in thermogenic and metabolic homeostasis. T3 and T4 are normally synthesized and released in response to a combined hypothalamic pituitary signal mediated by thyroid stimulating hormone (TSH) from the pituitary and thyrotropin releasing hormone from…
At a Glance Iodine is an essential element needed for the production of thyroid hormone. It is a component of thyroxine (T4 with four iodine molecules) and triiodothyronine (T3 with three iodine mol). Iodine is not produced by the body, so it must be part of the diet. It is found in various foods, including…
At a Glance The thyroid gland produces two related hormones, thyroxine (T4) and triiodothyronine (T3), which play a critical role in thermogenic and metabolic homeostasis. T3 and T4 are normally synthesized and released in response to a combined hypothalamic pituitary signal mediated by thyroid stimulating hormone (TSH) from the anterior pituitary and thyrotropin releasing hormone…
At a Glance Patients with thyroid stimulating hormone (TSH) deficiency, one type of central hypothyroidism, often present with symptoms similar to the more common primary hypothyroidism, including fatigue, lethargy, cold intolerance, and weight gain. Other symptoms of hypothyroidism seen in TSH deficiency include brittle fingernails; coarsening and thinning hair; puffy eyes; pale, dry skin; weakness;…
