Hypomagnesemia / Hypermagnesemia
Magnesium abnormalities rarely live alone — look at potassium, calcium, kidney function, medications, and symptoms.
Low magnesium: look for losses
GI losses, poor intake, alcohol use, diuretics, proton-pump inhibitors, and other renal or GI losses are common contributors. Pair the magnesium with potassium and calcium.
Refractory potassium is a clue
Hypomagnesemia can increase urinary potassium loss. Persistent hypokalemia despite appropriate replacement should prompt attention to magnesium rather than treating the two values as unrelated.
High magnesium: kidneys + exposure
Hypermagnesemia is uncommon when kidney function is intact. Review CKD/AKI and magnesium-containing supplements, antacids, laxatives, or therapeutic exposure.
Symptoms determine significance
Low magnesium can increase neuromuscular and arrhythmia risk; high magnesium can produce progressive weakness, reduced reflexes, hypotension, bradycardia, altered mental status, and respiratory depression.
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