View source for Hypoparathyroidism

==Background==
*Parathyroid hormone (PTH) increases osteolysis, renal tubular resorption of calcium, and renal synthesis of 1,25-dihydroxycholecalciferol AND inhibits renal tubular reabsorption of phosphate and bicarbonate, leading to net INCREASE in serum calcium
*Hypoparathyroid thus results in [[hypocalcemia]] with [[hyperphosphatemia]]

===Causes===
*Iatrogenic: 
**Anterior neck surgery or radiation (e.g. resection of multiple parathyroid adenomas, thyroidectomy); may be transient
**steroids, diuretics, antiepilptics
*Congenital (e.g. [[DiGeorge syndrome]])
*Malignancy
*Autoimmune
*Damage from [[Heavy metals]] (e.g. copper in [[Wilson's disease]])
*Functional hypoPTH from [[hypomagnesemia]]

==Clinical Features==
*See [[Hypocalcemia]], [[hyperphosphatemia]]

==Differential Diagnosis==
*[[Vitamin D deficiency]]
*Pseudohypoparathyroidism (renal resistance to PTH)
*Kidney disease
*Malabsorption
*Iatrogenic: 
**Anterior neck surgery or radiation (e.g. resection of multiple parathyroid adenomas, thyroidectomy); may be transient
**steroids, diuretics, antiepilptics
*Congenital (e.g. [[DiGeorge syndrome]])
*Malignancy
*Autoimmune
*Damage from [[Heavy metals]] (e.g. copper in [[Wilson's disease]])
*Functional hypoPTH from [[hypomagnesemia]]

==Evaluation==
*CMP
**Low serum calcium 
**Normal alk phos
*PTH (low or inappropriately normal in setting of hypocalcemia)
*EKG
*Magnesium levels
*Phosphate levels (high)

==Management==
*Treat underlying condition
===Hypocalcemia===
''Avoid empiric treatment in patients taking digoxin due to risk for [[Stone Heart]]''
*Asymptomatic
**[[Calcium gluconate]] 1 gm PO Q6hrs
**Vitamin D (calcitriol) 0.2 mcg BID
*Symptomatic
**[[Calcium gluconate]]/[[calcium chloride|chloride]] 10mL of 10% soln IV over 10min
*Correct [[hypomag]] at same time (otherwise PTH is inhibited)
*Avoid phenothiazine [[antipsychotics]] (may precipitate extrapyramidal symptoms)
*Avoid [[furosemide]] (may worsen hypocalcemia)

==Disposition==
*Admit if symptomatic [[hypocalcemia]]

==See Also==
*[[Hypocalcemia]], [[hyperphosphatemia]]
*[[Electrolyte Abnormalities (Main)]]

==External Links==

==References==
<references/>

[[Category:Endocrinology]]
[[Category:FEN]]