Magnesium and Calcium Imbalances for the NCLEX

Calcium (Normal: 9.0-10.5 mg/dL)

Hypocalcemia

• Signs: Chvostek's sign (facial twitch), Trousseau's sign (carpal spasm), tetany, numbness/tingling, seizures
• Causes: hypoparathyroidism, post-thyroidectomy, inadequate vitamin D, pancreatitis
• Treatment: IV calcium gluconate (slow), oral calcium supplements, vitamin D

Hypercalcemia

• Signs: "Stones, bones, groans, moans" - kidney stones, bone pain, GI distress, confusion
• Causes: hyperparathyroidism, malignancy, immobilization, excessive calcium/vitamin D
• Treatment: IV normal saline, loop diuretics (furosemide), calcitonin

Magnesium (Normal: 1.3-2.1 mEq/L)

Hypomagnesemia

• Signs: tremors, hyperactive DTRs, seizures, cardiac arrhythmias (similar to hypokalemia)
• Causes: alcoholism, malnutrition, diuretics, diarrhea
• Cannot correct hypokalemia without first correcting hypomagnesemia

Hypermagnesemia

• Signs: decreased DTRs, respiratory depression, hypotension, cardiac arrest
• Causes: renal failure, excessive MgSO4 (preeclampsia treatment)
• Antidote: calcium gluconate

Review our Electrolyte cheat sheet and Fluid & Electrolyte deep dive.