Asterixis (also called hepatic flap or liver flap) is a characteristic finding in:

• Hepatic encephalopathy (liver disease)
• Uremic encephalopathy (renal failure)
• CO₂ retention (respiratory failure)

It is caused by metabolic disturbance affecting motor control in the brain. Tested by asking the patient to extend wrists with arms outstretched — irregular, flapping tremor results.

Other important signs to differentiate:

• Chvostek's sign: Facial muscle twitching on tapping cheek → hypocalcemia
• Trousseau's sign: Carpal spasm with BP cuff inflation → hypocalcemia
• Kernig's sign: Resistance to knee extension with hip flexed → meningitis