Dysphagia is the term used to describe swallowing disorders in which one or more of the structures involved in the act of swallowing are impaired in their function or their interaction. The disorder can occur when eating, drinking or swallowing one's own saliva.

Swallowing disorders can occur in a variety of diseases:

• Diseases of the central nervous system, e.g. stroke, traumatic brain injury, Parkinson's disease or multiple sclerosis
• Diseases of the peripheral nervous system, e.g. nerve damage due to inflammation or lesions
• Structural changes in the oral cavity, pharynx, larynx, thyroid or esophagus, e.g. after surgery, tumor removal, radiation or chemotherapy
• Changes in behavior, cognition or drive, e.g. in dementia or mental illnesses

Unrecognized swallowing problems can result in malnutrition and dehydration. This in turn favors infections of the upper airways and urinary tract. There is also a risk of pneumonia due to aspiration, i.e. unnoticed choking on food. Overall, the affected person's quality of life can be severely impaired, depending on the severity of the restriction.