Swallowing is an essential life function. We swallow saliva approximately once per minute during the day and we continue to swallow as we sleep, albeit far less frequently. Nutrition and hydration are also important reasons why we swallow. One goal of swallowing is to efficiently move food and liquid into the stomach. To do this, we first coordinate several parts of the oral cavity (tongue, lips, hard and soft palates, jaw, cheeks) to break food down and then to propel food and liquid into the throat. Muscles of the throat (pharynx) continue to push food into the esophagus before it reaches the stomach. These functions can help to keep food from sticking in the throat, which could lead to choking (severe difficulty breathing because of food obstruction). Another goal of swallowing is to prevent food or liquid from entering certain parts of the respiratory tract including the larynx (voice box), trachea (wind pipe) and lungs. This is an intricate process that requires the larynx to close as food or liquid passes behind it. In addition to these movements, sensation is critical for keeping track of the position of food, liquid, and each part of the oral cavity and throat. Although complex, these events occur accurately and quickly while in multiple bodily positions, often with little thought. Swallowing naturally changes between birth and older adulthood and can remain functional throughout life.
Dysphagia is the medical term for swallowing disorders that can affect humans across the age span. Oropharyngeal dysphagia specifies impaired sensation and/or movements within the oral cavity and/or throat that lead to swallowing disorders. These impairments can lead to significant amounts of residue (food or liquid remaining in the oral cavity or throat after the swallow) and/or penetration and aspiration. Penetration occurs when food or liquid enters the larynx and aspiration occurs when the food has advanced deeper than the larynx to the trachea. Dysphagia can range between mild issues to very severe deficits, leading to devastating health and quality of life consequences. Treatments for dysphagia might include modifying or eliminating certain types of foods and liquids (i.e. thicker liquids), swallowing with the head and neck in alternate positions (i.e. turn head to the side), exercises, substitute forms of nutrition (feeding tube), or surgery.