Swallowing involves a sequence of actions as the food moves from the mouth to the stomach.

These actions include:

• After chewing, the tongue propels the food into the back of the throat.
• The top of the esophagus opens.
• Muscles in the throat propel the food into the esophagus.
• Muscles in the wall of the esophagus propel the food down the esophagus.
• The top of the esophagus closes.
• The bottom of the esophagus opens.
• Food enters the stomach.
• The bottom of the esophagus closes, preventing food from backing up into the esophagus after it reaches the stomach.

Difficulty swallowing may be caused by the following processes:

• Weakness of the muscles that regulate swallowing
• Obstruction of the esophagus
• Narrowing of the esophagus
• Irritation of the esophagus
• Injury to the esophagus

Common causes of difficulty swallowing include:

• Allergic reactions
• Acute angioedema
• Alcohol intoxication
• Drug abuse
• Drug side effect causing difficulty swallowing:
• Gastroesophageal reflux disease
• Head injury
• Mouth swelling
• Peptic ulcer disease
• Throat swelling
• Tongue swelling

Less common causes of difficulty swallowing include:

• Achalasia
• Alzheimer's disease
• Amyotrophic lateral sclerosis
• Cerebral palsy
• Chagas disease
• Cystic fibrosis
• Dementia
• Esophageal atresia:
• Failure of the esophagus to develop normally
• Esophageal cancer
• Esophageal stricture
• Laryngeal cancer
• Multiple sclerosis
• Muscular dystrophy
• Myasthenia gravis
• Nasopharyngeal carcinoma
• Parkinson's disease
• Schatzki's ring
• Scleroderma
• Stroke
• Thyroid cancer
• Transient ischemic attack
• Trichinosis