Air hunger is the urge to breathe, which is caused by the detection of high levels of carbon dioxide in the blood by sensors in the carotid sinus. It is one of the body’s homeostatic mechanisms to ensure proper oxygenation. Air hunger may be caused by insufficient pulmonary minute ventilation, a sustained breath-hold constriction of the alveoli of the lungs, as in asthma, or high ambient levels of carbon dioxide in the air. Air hunger can be very distressing and triggers strong reactions to restore breathing. Air hunger is caused due to excess of carbon dioxide rather than lack of oxygen.