The rapid, deep, and labored breathing of people who have acidosis. Kussmaul breathing is named for Adolph Kussmaul, the 19th century German doctor who first noted it. Also called "air hunger".
The cause of Kussmaul breathing is respiratory compensation for a metabolic acidosis, most commonly occurring in diabetics in diabetic ketoacidosis. Blood gases on a patient with Kussmaul breathing will show a low PCO2 because of a forced increased respiratory rate (blowing off the carbon dioxide).