This document provides information on causes and types of airway obstruction, and how to perform the Heimlich maneuver. It discusses anatomical and mechanical causes of obstruction. For severe obstruction, where the casualty cannot speak, cough, or breathe, abdominal thrusts or back blows are demonstrated to dislodge foreign objects for adults, children, and infants. If the casualty becomes unconscious, procedures for performing finger sweeps and modified CPR to clear the airway are described.