Definition of Dysphagia
Dysphagia is defined as difficulty in swallowing food (solid or semi-solid), liquid, or both, which can occur during any phase of the swallowing process from the mouth to the stomach. 1
Types of Dysphagia
Dysphagia can be classified based on the location where the swallowing difficulty occurs:
Oropharyngeal dysphagia: Difficulty initiating the swallowing process, often presenting as food sticking in the throat, globus sensation (feeling of a lump in the throat), coughing or choking during swallowing, nasal-quality voice, nasal regurgitation, food dribbling from the mouth, or difficulty initiating swallow or chewing 2
Esophageal dysphagia: Sensation that swallowed food stops in the chest or retrosternal area, often accompanied by pain, heartburn, regurgitation, or vomiting 2, 3
Pathophysiology of Dysphagia
Dysphagia occurs when there are impairments in one or more phases of the normal swallowing process:
Oral phase: Involves bolus manipulation, chewing, and tongue movement to propel food toward the pharynx (under voluntary control) 2
Pharyngeal phase: Involves elevation of the soft palate, multiple levels of laryngeal protection, pharyngeal muscle contraction, and opening of the upper esophageal sphincter (partially voluntary and partially involuntary) 2
Esophageal phase: Consists of peristaltic wave contractions that move the food bolus through the esophagus (under involuntary control) 2
Clinical Manifestations
Dysphagia can present with various symptoms depending on the affected phase:
Oropharyngeal symptoms: Coughing/choking during swallowing (due to laryngeal penetration or aspiration), nasal voice or nasal regurgitation (due to soft palate insufficiency), food dribbling from mouth, and difficulty initiating swallow 2
Esophageal symptoms: Retrosternal pain, heartburn, regurgitation, vomiting, and sometimes respiratory symptoms 3
Complications: Aspiration pneumonia, malnutrition, dehydration, and weight loss 4, 1
Causes of Dysphagia
Dysphagia is not a disease itself but results from various medical conditions:
Neurological disorders: Stroke, Parkinson's disease, dementia, myasthenia gravis, amyotrophic lateral sclerosis 2
Structural abnormalities: Tumors, strictures, webs, rings, diverticula 5
Motility disorders: Achalasia, diffuse esophageal spasm, hypermotile esophagus 3
Other causes: Gastroesophageal reflux disease, medication effects, post-surgical changes, aging-related changes 2
Diagnostic Approach
Dysphagia is evaluated through:
Imaging studies: Videofluoroscopy (modified barium swallow), esophagography (barium swallow), dynamic and static imaging of the pharynx 2
Endoscopic procedures: Direct visualization of structural abnormalities 2
Other tests: Manometry, electromyography, pH determinations 3
Special Considerations in Older Adults
Aging itself contributes to swallowing changes through sarcopenia affecting swallowing muscles, decreased tongue force generation, slower chewing, and reduced salivary flow 2
Medications commonly taken by older adults can exacerbate swallowing difficulties 2
Dysphagia in older adults has been suggested as its own geriatric syndrome due to its high prevalence and serious consequences 2
Clinical Pearls and Pitfalls
Abnormalities of the mid or distal esophagus or gastric cardia may cause referred dysphagia to the upper chest or pharynx, whereas pharyngeal abnormalities rarely cause referred dysphagia 2
Silent aspiration (aspiration without cough response) is common in patients with impaired laryngeal sensation 2
Esophageal dysphagia that begins with solids only but progresses to include liquids suggests a mechanical issue (tumor/stricture), while dysphagia for both solids and liquids from onset suggests a motor problem like achalasia 2