Hypoparathyroidism
Hypoparathyroidism is deficient parathyroid hormone secretion or action, most often after neck surgery, causing hypocalcaemia with hyperphosphataemia; acute symptoms need emergency calcium treatment, while chronic care balances active vitamin D and calcium against hypercalciuria and renal injury.
Definition
Hypoparathyroidism is insufficient parathyroid hormone secretion or action, producing hypocalcaemia with an inappropriately low or normal PTH and usually hyperphosphataemia. It is most often postsurgical in adults, but may be autoimmune, genetic, infiltrative or functional from magnesium depletion.
First principles
Loss of PTH lowers calcium and raises phosphate
PTH normally increases renal calcium reabsorption, promotes renal phosphate excretion and stimulates renal activation of vitamin D. When PTH is absent or ineffective, calcium falls, phosphate is retained and calcitriol production falls, reducing intestinal calcium absorption. The biochemical pattern is hypocalcaemia with an inappropriately low or normal PTH and often hyperphosphataemia.
This page is exam revision material, not medical advice, and must not be used for patient care. Always check drug doses against the BNF and current guidance. Full disclaimer.