Exam Guide
What Chvostek's Sign Reveals About Calcium
Renal & Electrolytes · Question from the ATI RN Medical-Surgical 2023 Proctored Exam study set
Correct answer: B. Hypocalcemia
Why this is the answer
Chvostek's sign — facial muscle twitching when the facial nerve is tapped near the ear — reflects the neuromuscular irritability caused by low serum calcium. Hypokalemia (A) causes muscle weakness and cramping rather than this specific facial twitch response. Hypernatremia (C) isn't linked to Chvostek's sign at all. Hypermagnesemia (D) actually does the opposite — it depresses neuromuscular excitability rather than increasing it, so it would blunt reflexes, not trigger this kind of twitching.
The bigger concept
Chvostek's and Trousseau's signs are the two classic bedside tests for hypocalcemia-related tetany — Chvostek's taps the facial nerve, while Trousseau's inflates a blood pressure cuff to trigger carpal spasm. Both point to the same underlying problem: calcium is too low, and the nerves are firing too easily.
Related Renal & Electrolytes practice questions
- High Magnesium in Renal Failure: What to Monitor
- Positive Trousseau's Sign: What It Means
- Why Anemia Is Common in Chronic Renal Failure
- Defining the Oliguric Phase of Acute Renal Failure
- Furosemide and Potassium Loss
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