Acute upper airway obstruction may have any of a number of causes including viral and bacterial infections, fire or inhalation burns, chemical burns and reactions, allergic reactions, foreign bodies, and trauma. The blockage can be complete or partial. Mild obstruction may result in air hunger, while more severe obstruction can lead to cyanosis (a bluish discoloration of the skin or mucous membranes caused by lack of oxygen in the blood), confusion, or unconsciousness. Complete obstruction, if not corrected, leads to rapid suffocation and death.