When swallowing, a piece of tissue called the epiglottis normally prevents food from entering your lungs by covering your trachea, or windpipe. From time to time, you may accidentally take food into your trachea while you're eating. If you're healthy and have a strong immune system, you may not have any complications from an isolated incident. However, inhaling food, known as aspiration, can cause serious complications, especially if you have a condition that makes you aspirate food or fluids on a regular basis.
Blockage of respiratory passage may cause skin to turn a bluish color due to lack of oxygen. Aspirating small amounts of food frequently during meals may cause development of a cough with foul-smelling sputum, bad breath, increased swallowing difficulty, fatigue and dizziness.
Food or fluids in your air passages may trigger an inflammatory response as your lungs react to the foreign substance. Fluid may accumulate in your lungs if a passage is blocked. If an infection occurs, you may develop bacterial pneumonia.