At a Glance Congenital adrenal hyperplasia (CAH) includes a group of autosomal recessive disorders that lead to a deficiency in the steroid synthesis pathway for aldosterone and/or cortisol. The clinical manifestations of CAH are varied and depend, in large part, on the extent of aldosterone or cortisol deficiency. In addition, in some forms of CAH,…
At a Glance Secondary hyperparathyroidism is an overproduction of parathyroid hormone (PTH) production secondary to a chronic abnormal stimulus for PTH production. The most common causes are chronic renal failure and vitamin D deficiency. Secondary hyperparathyroidism often develops early in chronic kidney disease, even before dialysis or transplantation is considered. Most patients with end-stage renal…
At a Glance The milk-alkali syndrome is an acquired condition with hypercalcemia and relative metabolic alkalosis. The disease classically occurs in patients drinking large amounts of milk and/or chronically taking high doses of calcium carbonate (either as antacid or calcium supplement) or sodium bicarbonate. With the shift toward histamine-2 receptor antagonists (e.g., ranitidine) and proton…
At a Glance Pseudohypoparathyroidism is a heterogeneous group of rare disorders whose hallmark is insensitivity to parathyroid hormone (PTH). These disorders may present with defects isolated to the parathyroid gland (type Ib or II) or as a syndrome with a constellation of developmental and skeletal defects (type Ia). The most well-known of these is Albright…
At a Glance There are two main mechanisms by which cancer can lead to hypercalcemia. The first and most common is local action on bone as may be seen in multiple myeloma or carcinomas (e.g., breast or prostate) that metastasize to bone. The second mechanism is by tumors that secrete humoral factors that stimulate bone…
At a Glance Primary hyperparathyroidism is a syndrome of excessive parathyroid hormone (PTH) secretion by the parathyroid glands. The most common cause (> 95%) is a sporadic, single parathyroid adenoma. Less common are parathyroid hyperplasia (~2.5%), parathyroid carcinoma, and multiple adenomas. Many patients are asymptomatic and present only with an incidental finding of elevated serum…
At a Glance Hypoparathyroidism is a relatively rare disorder. There are two major causes of hypoparathyroidism: deficient secretion and/or action of parathyroid hormone (PTH) resistance to PTH (pseudohypoparathyroidism) Deficient PTH action or secretion can result from surgical removal of the parathyroid glands, iron overload, autoimmune disease, DiGeorge syndrome, inherited defects in the PTH gene, and…
