Swallowing disorders and esophageal passage disorders

Swallowing is a complex, coordinated process of transporting food, liquids or saliva from the mouth to the stomach. It involves 3 main stages:

1. Oral (voluntary)
2. Pharyngeal (involuntary)
3. Esophageal (involuntary)

Be careful! Epiglottis has to seal the airway to prevent aspiration

Dysphagia

Dysphagia is the difficulty in swallowing or impaired passage of food from the pharynx to the stomach.

Cleveland Clinic. (2023, August 20). Dysphagia (difficulty swallowing): What it is, causes & treatment. Cleveland Clinic.

• Oropharyngeal dysphagia
  • difficulty emptying material from the oropharynx into the esophagus due to abnormal function proximal to the esophagus
  • often in patients with neurological conditions or muscular disorders that affect skeletal muscles)
  • typically associated with coughing or choking
• Esophageal dysphagia
  • difficulty passing food down the esophagus
  • results from motility disorder or mechanical obstruction
• Motility related dysphagia (dysphagia due to a neurological or muscular defect)
• Structural dysphagia (dysphagia due to mechanical or anatomical obstruction)

Symptoms of Dysphagia

• Patient complains of "sticking" or something getting caught in the esophagus
• Odynophagia - pain when swallowing in the throat of chest
• coughing
• choking
• Pyrosis
• Persistent sore throat

Aphagia

inability to swallow

Achalasia

Cleveland Clinic. (2025, May 7). Achalasia (cardiospasm). Cleveland Clinic.

Achalasia is the impaired relaxation of the lower esophageal sphincter due to degeneration of inhibitory neuron within the esophageal walls. (A = without, achalasia = relaxation)

• Swallowing is controlled through excitatory (acetylcholine, substance P) and inhibitory (NO, VIP) neurohumoral substances
• Atrophy of inhibitory neurons in the Auerbach plexus → lack of inhibitory neurotransmitters (e.g., NO, VIP) → inability to relax and increased resting pressure of the LES, as well as dysfunctional peristalsis → esophageal dilation proximal to LES

The cause of Achalasia is unknown, but can be associated with Autoimmune processes, genetic factors, and/ or viral infections. It can be classified based on:

• Primary - idiopathic destruction of myenteric plexus
• Secondary - cancer, amyloidosis or infections like Chagas disease (by Trypanosoma cruzi)

It can also be classified as:

• Type 1 Achalasia (esophagus muscles barely contract, food moves down by gravity)
• Type 2 Achalasia (pressure builds up in esophagus and causes it to become compressed)
• Type 3 Achalasia (abnormal contractions at the bottom of esophagus causing severe chest pain)

Symptoms of Achalasia

• feeling of food "sticking" or caught in esophagus
• Regurgitation (food backing up in mouth after being swallowed)
• chest pain (can be severe and awaken the person from sleep)
• Pyrosis
• coughing
• choking

Complications of Achalasia

• Pulmonary complications e.g. pneumonia, abscess, asthma (from aspiration)
• Megaesophagus
• Increased risk of esophageal (Squamous cell carcinoma) cancer

Structural disorders of esophageal passage

Cleveland Clinic. (2024, February 2). Esophageal strictures: Symptoms, causes & treatment. Cleveland Clinic.

Esophageal stenosis and stricture

Stenosis is an abnormal narrowing of the esophageal lumen

Structure is an abnormal narrowing of the esophageal lumen, often an acquired fibrotic narrowing caused by chronic inflammation, reflux, injury or malignancy

Esophageal webs

An esophageal web is a thin membranous fold of esophageal tissue that partially protrudes into the lumen and may partially obstruct it.

• usually in the upper esophagus
• can cause intermittent dysphagia (solid food)
• often associated with Plummer Vinson syndrome (includes triad of iron deficiency anemia, postcricoid dysphagia and esophageal webs)
• Its pathophysiology is poorly understood, but chronic inflammation can irritate the esophageal wall and produce these lesions

Cleveland Clinic. (2025, May 20). Zenker’s diverticulum: Symptoms, causes & treatment. Cleveland Clinic.

Esophageal diverticulum

An esophageal diverticulum is an outpouching of the esophageal wall (mainly esophageal mucosa). It is usually asymptomatic, or may have symptoms like regurgitation or dysphagia.

There are 2 types of diverticulum

• True diverticulum (involves all layers of the wall)
• False diverticulum (involves only mucosa and submucosa)

Esophageal diverticulum is formed by either pulsion or traction. Pulsion diverticula occur when there is an inadequate relaxation of either the upper or lower esophageal sphincter resulting in increased intraluminal pressure and subsequent herniation of the esophageal wall at an area of weakness; and usually occur in the setting of dysmotility of the esophagus. Traction diverticula occur when there is an external force on the esophageal wall such as mediastinal inflammation that adheres and pulls on the esophageal wall creating a defect or diverticulum.

Zenker diverticulum

Zenker diverticulum is a false diverticulum that forms in the pharyngoesophageal region (above the cricopharynxgeus, through a weak area Killian's triangle).

References

1. Panara K, Ahangar ER, Padalia D. Physiology, Swallowing. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; Updated 2023 Jul 24. Available from: https://www.ncbi.nlm.nih.gov/books/NBK541071/
2. Lynch KL, Nguyen M. Dysphagia. Merck Manual Professional Edition [Internet]. Kenilworth (NJ): Merck & Co., Inc.; revised Feb 2026. Available from: https://www.merckmanuals.com/professional/gastrointestinal-disorders/esophageal-and-swallowing-disorders/dysphagia
3. AMBOSS. Dysphagia. Berlin: AMBOSS. Available from: https://next.amboss.com/us/article/Er08Qh?q=dysphagia
4. Johns Hopkins Medicine. Swallowing Disorders [Internet]. Baltimore (MD): Johns Hopkins Medicine. Available from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/swallowing-disorders
5. AMBOSS. Achalasia. Berlin: AMBOSS. Available from: https://next.amboss.com/us/article/ug0pC2?q=Achalasia
6. Lynch KL, Nguyen M. Achalasia. MSD Manual Professional Edition [Internet]. Rahway (NJ): Merck & Co., Inc.; revised Feb 2026. Available from: https://www.msdmanuals.com/professional/gastrointestinal-disorders/esophageal-and-swallowing-disorders/achalasia
7. Johns Hopkins Medicine. Achalasia [Internet]. Baltimore (MD): Johns Hopkins Medicine. Available from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/achalasia
8. Khan M, Jawad S, Averbach C. Esophageal Stricture. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. Available from: https://www.ncbi.nlm.nih.gov/books/NBK542209/
9. Pesce M, Zullo A. Esophageal Webs and Rings. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2026 Jan–. Available from: https://www.ncbi.nlm.nih.gov/books/NBK539771/
10. “Esophageal Diverticula.” StatPearls, by Julie Yam, Dustin L. Baldwin, and Sarah A. Ahmad, StatPearls Publishing, Available from: www.ncbi.nlm.nih.gov/books/NBK532858/