Swallowing: The WH’s of Dysphagia

Swallowing: The WH’s of Dysphagia

What is Dysphagia?

Dysphagia refers to a difficulty in the process of swallowing, where it takes more effort than normal to move food from the mouth to the stomach. Dysphagia can be associated with pain (odynophagia) and is common among young babies and older adults.


How do we swallow?

The normal process of swallow is a complex mechanism, involving the coordination of the brain, muscles, nerves, valves, esophagus and the stomach, to ensure passing of food from the mouth to the stomach.

The swallow process typically takes place in three phases. The bolus is represented in green color in the picture.

In the first phase, food or liquid is contained in the mouth by the tongue and palate (oral cavity). This phase is voluntary and under our control.

oral phase


The second phase begins when the brain makes the decision to swallow. At this point, a complex series of reflexes begin. The food is thrust from the oral cavity into the throat (pharynx). A muscular valve at the bottom of the pharynx opens, allowing food to enter the esophagus, and other muscles close the airway (trachea) to prevent food from entering the airways. This second phase takes less than half a second, and is involuntary.

pharyngeal phase

The third phase starts when food enters the esophagus. The esophagus, which is about nine inches long, is a muscular tube that produces waves of coordinated contractions (peristalsis). As the esophagus contracts, a muscular valve at the end of the esophagus opens and food is propelled into the stomach. The third phase of swallowing takes six to eight seconds to complete and is involuntary.

esophageal phase

Dysphagia can be caused by a difficulty anywhere in the three phases of the swallowing process.

Types of Dysphagia

Oral phase dysphagia – The problem is in the mouth, sometimes caused by tongue weakness after a stroke, difficulty chewing food, or problems transporting food from the mouth.

Pharyngeal phase dysphagiaThe problem is in the throat. Issues in the throat are often caused by a neurological problem that affects the nerves (such as Parkinson’s disease, stroke, or amyotrophic lateral sclerosis).

Esophageal dysphagia – The problem is in the esophagus. This is usually because of a blockage or irritation. Often, a surgical procedure is required.

Why does Dysphagia occur?

There are many possible caused of dysphagia. The few common ones are:

  • Amyotrophic lateral sclerosis – An incurable form of progressive neurodegeneration; over time, the nerves in the spine and brain progressively lose function.
  • Achalasia – Lower esophageal muscle does not relax enough to allow food into the stomach, resulting in difficulty in esophageal phase.
  • Diffuse spasmUncoordinated contraction of esophageal muscles, hampering peristalsis.
  • Stroke – Death of brain cells due to lack of oxygen and reduced blood flow causing dysphagia.
  • Esophageal ring – Narrowing of a small portion of the esophagus, preventing solid foods from passing through it.
  • Eosinophilic esophagitis – Severely elevated levels of eosinophils (a type of white blood cell) in the esophagus, attacking the gastrointestinal system, leading to vomiting and difficulty with swallowing food.
  • Multiple sclerosis – The central nervous system is attacked by the immune system, destroying myelin, which normally protects the nerves, resulting in dysfunction of nervous system related to swallow.
  • Myasthenia gravis (Goldflam disease) – An autoimmune disorder where the muscles under voluntary control become easily tired and weak, resulting in weak/ difficult swallow coordination.
  • Parkinson’s disease and Parkinsonism syndromes – Parkinson’s disease is a gradually progressive, degenerative neurological disorder that impairs the patient’s motor skills, resulting in weak coordination of swallow.
  • Radiation – Patients who received radiation therapy (radiotherapy) to the neck and head area may have swallowing difficulties.
  • Cleft lip and palate – Types of abnormal developments of the face due to incomplete fusing of bones in the head, resulting in gaps (clefts) in the palate and lip to nose area, affecting the oral and pharyngeal phases of swallow.
  • Scleroderma – A group of rare autoimmune diseases where the skin and connective tissues become tighter and harden, making transport of bolus from mouth to stomach difficult.
  • Esophageal cancer – A type of cancer in the esophagus, usually related to either alcohol and smoking, or gastroesophageal reflux disease (GERD), affecting the esophageal phase of swallowing.
  • Esophageal stricture – Narrowing of the esophagus, often related to GERD, hampering the peristaltic movements.
  • Xerostomia (dry mouth) – There is not enough saliva to keep the mouth wet, and help in transport of the bolus.

Some patients have dysphagia and are unaware of it — in these cases, it may go undiagnosed and not be treated, raising the risk of aspiration pneumonia (a lung infection that can develop after accidentally inhaling saliva or food particles). Undiagnosed dysphagia may also lead to dehydration and malnutrition.

 How do we identify symptoms related to Dysphagia?

  • Choking when eatingchoking
  • Coughing or gagging when swallowing
  • Drooling
  • Food or stomach acid backing up into the throatweightloss
  • Recurrent heartburn
  • Hoarsenessheartburn
  • Sensation of food getting stuck in the throat or chest, or behind the breastbone.
  • Unexplained weight loss
  • Bringing food back up (regurgitation)
  • Difficulty controlling food in the mouth
  • Difficulty starting the swallowing process
  • Recurrent pneumonia
  • Inability to control saliva in the mouth


Patients experiencing any of the symptoms associated with difficulty in swallowing, must immediately contact a medical professional, for treatment.

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