Hamman's sign

Hamman's sign (rarely, Hammond's sign^[1] or Hammond's crunch^[2]) is a medical sign consisting of a crunching, rasping sound, synchronous with the heartbeat,^[3] heard over the precordium in spontaneous mediastinal emphysema. It is thought to result from the heart beating against air-filled tissues.

Hamman's sign
Differential diagnosis	pneumomediastinum

It is named after Johns Hopkins clinician Louis Hamman, M.D.^[4]

This sound is heard best over the left lateral position.^[5] It has been described as a series of precordial crackles that correlate with the heart beat rather than respiration.

Causes

Hamman's crunch is caused by pneumomediastinum or pneumopericardium, and is associated with tracheobronchial injury^[6] due to trauma, medical procedures (e.g., bronchoscopy) or rupture of a proximal pulmonary bleb. It can be seen with Boerhaave syndrome.

See also

• Hamman's syndrome