Ad
related to: parathyroid high but calcium normal range
Search results
Results from the WOW.Com Content Network
Symptoms of hyperparathyroidism are caused by inappropriately normal or elevated blood calcium excreted from the bones and flowing into the blood stream in response to increased production of parathyroid hormone. [1] In healthy people, when blood calcium levels are high, parathyroid hormone levels should be low.
Parathyroid hormone regulates serum calcium through its effects on bone, kidney, and the intestine: [5] In bone, PTH enhances the release of calcium from the large reservoir contained in the bones. [16] Bone resorption is the normal destruction of bone by osteoclasts, which are indirectly stimulated by PTH.
Serum calcium levels are usually elevated, and the parathyroid hormone level is abnormally high compared with an expected low level in response to the high calcium. A relatively elevated parathyroid hormone has been estimated to have a sensitivity of 60–80% and a specificity of approximately 90% for primary hyperparathyroidism. [9]
Calcium levels are often in the high normal range or slightly elevated. Commonly, the parathyroid hormone level is checked and may be slightly elevated or also on the high normal end. Normally, high calcium should cause low PTH and so this level of PTH is inappropriately high due to the decreased sensitivity of the parathyroid to calcium.
Intact PTH (iPTH, biologically active parathyroid hormone molecules) is measured with immunoradiometric or immunochemoluminescent assay. Elevated (or high-normal) iPTH with high urine calcium/creatinine ratio (more than 0.03) is suggestive of primary hyperparathyroidism, usually accompanied by low serum phosphate.
[10] [11] The parathyroid gland is located beside the thyroid gland in the neck, below and in front of the larynx and above the trachea. It is composed of four glands in total that monitor blood calcium levels via the calcium sensing receptors, a g-coupled protein receptor. [12] The parathyroid glands main role is calcium homeostasis.
The single major disease of parathyroid glands is overactivity of one or more of the parathyroid lobes, which make too much parathyroid hormone, causing a potentially serious calcium imbalance. This is called hyperparathyroidism ; it leads to hypercalcemia , kidney stones, osteoporosis, and various other symptoms.
Secondary hyperparathyroidism is the medical condition of excessive secretion of parathyroid hormone (PTH) by the parathyroid glands in response to hypocalcemia (low blood calcium levels), with resultant hyperplasia of these glands. This disorder is primarily seen in patients with chronic kidney failure.
Ad
related to: parathyroid high but calcium normal range