Chocking occurs when a foreign object becomes lodged in the airway, blocking breathing. For adults, abdominal thrusts are used - standing behind the person, placing one fist above the naval and pressing forcefully inward and upward until the obstruction is cleared. For pregnant or obese adults, chest thrusts are used instead. For infants, back slaps and chest thrusts are alternated until breathing resumes or the infant becomes unresponsive, at which point CPR is provided.