Hypocalcemia

Hypocalcemia
Specialty	Endocrinology
Symptoms	Numbness, muscle spasms, seizures, confusion[1][2]
Complications	Cardiac arrest[1][2]
Causes	Hypoparathyroidism, vitamin D deficiency, kidney failure, pancreatitis, calcium channel blocker overdose, rhabdomyolysis, tumor lysis syndrome, bisphosphonates[1][2]
Diagnostic method	Blood serum < 2.1 mmol/L (corrected calcium or ionized calcium)[1][2][3]
Treatment	Calcium supplements, vitamin D, magnesium sulfate.[1][2]
Frequency	~18% of people in hospital[4]

Hypocalcemia is a medical condition characterized by low calcium levels in the blood serum.^[5] The normal range of blood calcium is typically between 2.1–2.6 mmol/L (8.8–10.7 mg/dL, 4.3–5.2 mEq/L), while levels less than 2.1 mmol/L are defined as hypocalcemic.^[1][3][6] Mildly low levels that develop slowly often have no symptoms.^[2][4] Otherwise symptoms may include numbness, muscle spasms, seizures, confusion, or in extreme cases cardiac arrest.^[1][2]

The most common cause for hypocalcemia is iatrogenic hypoparathyroidism.^[2] Other causes include other forms of hypoparathyroidism, vitamin D deficiency, kidney failure, pancreatitis, calcium channel blocker overdose, rhabdomyolysis, tumor lysis syndrome, and medications such as bisphosphonates or denosumab.^[1] Diagnosis should generally be confirmed by determining the corrected calcium or ionized calcium level.^[2] Specific changes may also be seen on an electrocardiogram (ECG).^[1]

Initial treatment for severe disease is with intravenous calcium chloride and possibly magnesium sulfate.^[1] Other treatments may include vitamin D, magnesium, and calcium supplements.^[2] If due to hypoparathyroidism, hydrochlorothiazide, phosphate binders, and a low salt diet may also be recommended.^[2] About 18% of people who are being treated in hospital have hypocalcemia.^[4]