Chvostek's sign and Trousseau's sign: how to test for hypocalcemia

Chvostek's sign is twitching of the face when you tap the facial nerve in front of the ear. Trousseau's sign is a spasm of the hand when a blood pressure cuff stays inflated above the systolic pressure. Both show nerves made irritable by a low calcium level, and both can also appear with low magnesium.

Sources checked 18 October 2026.

Chvostek's sign

• How: tap over the facial nerve, just in front of the ear and below the cheekbone.
• Positive: twitching of the facial muscles on the same side, for example at the corner of the mouth or the nose.
• Reliability: low. StatPearls reports a positive sign in about 25% of healthy people, and a negative sign in about 29% of people with hypocalcemia.

Trousseau's sign

• How: inflate a blood pressure cuff on the upper arm to about 20 mm Hg above the systolic pressure and keep it there for 2 to 3 minutes. Open RN teaches 3 minutes.
• Positive: carpal spasm. The wrist and the knuckle joints flex, the finger joints straighten and the fingers come together. It is sometimes called the obstetrician's hand.
• Reliability: high. StatPearls gives a sensitivity of 94% and a specificity of 99% for hypocalcemia. It is positive in 1 to 4% of healthy people.

The two signs compared

Hypocalcemia: levels, causes and signs

StatPearls gives the normal total calcium as about 8.5 to 10.5 mg/dL (about 2.1 to 2.6 mmol/L), and ionized calcium as about 4.65 to 5.25 mg/dL. Laboratories differ, so use the range on the report. A low albumin lowers the total calcium without changing the ionized calcium, so the total is corrected for albumin.

Common causes:

• Hypoparathyroidism after thyroid or parathyroid surgery.
• Vitamin D deficiency and chronic kidney disease.
• Low magnesium.
• Acute pancreatitis.
• Massive blood transfusion, because citrate binds calcium.
• Alkalosis, which makes more calcium bind to albumin.

Signs: numbness around the mouth, tingling in the fingers and toes, muscle cramps and tetany. Severe hypocalcemia can cause laryngospasm, seizures and arrhythmias. The ECG shows a prolonged QT interval.

What the nurse does

• Report new tingling, twitching or a positive sign, especially after neck surgery or a large transfusion.
• Watch the airway. Stridor or a hoarse, high-pitched voice can mean laryngospasm.
• Put the client on a cardiac monitor if ordered and look for a long QT interval.
• Take seizure precautions when hypocalcemia is severe.
• Expect IV calcium for severe symptoms. StatPearls prefers calcium gluconate, because it damages tissue less than calcium chloride if it leaks from the vein. It is given over 10 to 20 minutes.
• Expect the magnesium to be corrected too. Calcium does not stay up while magnesium is low.

How to remember it

• C for cheek. Chvostek's is the cheek tap.
• T for tourniquet. Trousseau's uses a cuff on the arm.
• Low calcium, long QT. High calcium shortens it.

More on fluids and electrolytes: hypotonic vs hypertonic IV fluids, third spacing, potassium and the ECG, hyperkalemia ECG changes and hypokalemia ECG changes.

Practice questions

1. Question 1Multiple choiceReduction of Risk Potential
   The day after a total thyroidectomy, a client reports tingling around the mouth. When the nurse taps in front of the ear, the corner of the mouth twitches. What should the nurse do?

   Report a positive Chvostek's sign and the tingling to the provider at once.Document a normal facial nerve response.Encourage the client to breathe into a paper bag.Give the prescribed levothyroxine early.
   Check answer
2. Question 2Multiple choiceReduction of Risk Potential
   How does the nurse check for Trousseau's sign?

   Inflate a blood pressure cuff above the systolic pressure for about 3 minutes and watch the hand.Tap the facial nerve in front of the ear.Tap the patellar tendon and grade the reflex.Ask the client to make a fist for 30 seconds.
   Check answer
3. Question 3Multiple responsePhysiological Adaptation
   Which conditions can cause hypocalcemia? Select all that apply.

   Removal of or injury to the parathyroid glandsLow magnesiumA massive blood transfusionAcute pancreatitisPrimary hyperparathyroidism
   Check answer
4. Question 4Multiple choicePhysiological Adaptation
   A client's ionized calcium is low. Which ECG change does the nurse expect?

   A prolonged QT intervalTall, peaked T wavesA U wave after the T waveA shortened QT interval
   Check answer
5. Question 5Multiple choiceReduction of Risk Potential
   Which statement about the two bedside signs is accurate?

   Chvostek's sign can be positive in healthy people, so Trousseau's sign is the more reliable of the two.A negative Chvostek's sign rules out hypocalcemia.Both signs are specific to calcium.Trousseau's sign is tested by tapping the wrist.
   Check answer