Swallowing is a very complex act, requiring the normal function of the brain, several nerves and muscles, two muscular valves, and an open, unconstricted esophagus, or swallowing tube.
The swallowing tract extends from the mouth to the stomach. The act of swallowing normally occurs in three phases. In the first phase, food or liquid is contained in the mouth by the tongue and palate (oral cavity). This phase is the only one we can control.
The second phase of swallowing 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). At the same time, two other events occur: 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 of swallowing takes less than half a second.
The third phase of swallowing begins 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.
A wide range of diseases can cause swallowing problems, including:
Disturbances of the brain such as those caused by Parkinson's disease, multiple sclerosis, or ALS (amyotrophic lateral sclerosis, or Lou Gehrig's disease).
Oral or pharynx muscle dysfunction such as from a stroke.
Loss of sphincter muscle relaxation (termed "achalasia").
Esophageal narrowing such as from acid reflux or tumors.
How Do I Know If I Have a Swallowing Problem?
Under normal circumstances, individuals rarely choke during a meal. Occasionally, food will stick in the esophagus for a few seconds (especially solid foods) but will pass spontaneously or can be washed down easily with liquids. However, there are a number of symptoms that require evaluation for a possible swallowing problem, including:
Frequent choking on food
Hesitancy in food passage for more than a few seconds
Pain when swallowing
Recurring pneumonia (an indication that food may be going into the lungs rather than the esophagus)
Immediate medical attention is needed when food becomes lodged in the esophagus for more than 15 minutes and doesn't pass spontaneously or with liquids.
Some people are unaware that they have swallowing problems because they compensate unconsciously by choosing foods that are easier to eat, or they eat more slowly. However, untreated swallowing problems increases the risk for choking or having large pieces of solid food lodge in the esophagus.
How Are Swallowing Problems Diagnosed?
If you think you have a swallowing problem, talk to your health care provider. Tests are available to determine the cause of a swallowing problem and may include:
Cineradiography: An imaging test in which a camera is used to film internal body structures. During the test, you will be asked to swallow a barium preparation (liquid or other form that lights up under X-ray). An X-ray machine with videotaping capability will be used to view the barium preparations movement through the esophagus. This is often performed under the guidance of a speech pathologist, an expert in swallowing as well as speech.
Upper endoscopy: A flexible, narrow tube (endoscope) is passed into the esophagus and projects images of the inside of the pharynx and esophagus on a screen for evaluation.
Manometry: This test measures the timing and strength of esophageal contractions and muscular valve relaxation.
Impedance and pH test: This test can determine if acid reflux is causing a swallowing problem.