Hypercalcemia is a condition that the concentration of serum ionized calcium unusual increase and calcium concentration is higher than 2.75mmol / L. Clinical serum albumin concentration on the most important factor, because albumin in blood circulation are the major calcium-binding protein. At lower serum albumin serious cases (such as in patients with malignant tumors), normal serum total calcium concentration in fact represent the abnormally high concentration of ionized calcium. PH also affects the serum calcium and protein combination alkalosis can lower the plasma calcium concentration, the increased acidosis can. When entering the extracellular calcium (intestine, bone) than the calcium from the trigger hypercalcemia. Has the cause of hypercalcemia caused by two major categories: PTH-dependent and non-PTH-dependent. Serum calcium is generally believed that at 3.75mmol / L or more, can be high calcium crisis happened, deal with life-threatening misconduct.
Hypercalcemia are the early changes in kidney function is impaired concentration. Calcium is the orange anti-cAMP agents, hypercalcemia ADH to reduce the role of collecting duct, ADH and hinder the receptor-binding and thus interfere with the normal effects of ADH. Hypercalcemia and renal blood flow also enable help to reduce the rate of glomerular filtration. Hypercalcemia within 48 hours after renal ultrastructural changes can be seen, there Henry ramus, distal tubules, collecting duct of the edema, calcification of basement membrane, epithelial shedding, such as necrosis.