Swallowing Difficulties

  • Basics

    The medical term for swallowing difficulties is dysphagia Figure 01. Swallowing requires normal function and coordination of the brain, nerves, muscles, teeth, and salivary glands. The swallowing process begins in the mouth and ends when food or liquids arrive in the stomach; dysphagia may result from conditions that affect at any point along this path.

    Click to enlarge: Anatomy of the digestive system

    Figure 01. Anatomy of the digestive system

    Dysphagia is a common symptom in the general population, but dysphagia is most common among older adults. Although anyone can experience dysphagia, the condition is most common in older adults. Up to 40% of nursing home residents are affected by the condition.

    All cases of dysphagia warrant medical attention. Dysphagia always requires medical attention, even if the symptoms are mild. Dysphagia can be an early warning symptom of a serious underlying condition. Furthermore, untreated swallowing disorders can lead to complications, including weight loss, malnutrition, dehydration, choking, a type of pneumonia caused by inhalation of food liquid, gases, dust, or fungi (aspiration pneumonia), and even death.

    The diagnosis and treatment of dysphagia usually involves a team of health care professionals. Several different types of doctors may help evaluate and treat dysphagia, including a primary care doctor, an otolaryngologist who is an ear, nose, and throat (ENT) doctor, a radiologist, a doctor who specializes in digestive conditions (gastroenterologist), and a rehabilitation specialist. The team usually also includes other health care professionals with specific expertise, such as speech-language pathologists, swallowing therapists, physical or occupational therapists, and dietitians.

    Because dysphagia can be caused by numerous underlying conditions, the treatment is tailored to the specific cause of dysphagia. Treatment may include drug therapy, swallowing rehabilitation, surgery, or some combination of these measures.

  • Causes

    There are two broad types of swallowing difficulties: one type affects the mouth and upper throat (oropharyngeal dysphagia), and the other type affects the esophagus (esophageal dysphagia) [Figure 1]. Oropharyngeal dysphagia refers to swallowing difficulties that affect the mouth and/or the upper throat (pharynx). In contrast, esophageal dysphagia refers to swallowing difficulties that affect the tube (esophagus) that connects the pharynx to the stomach. These two types of dysphagia can usually be distinguished based on a person's medical history (specific symptoms), the specific signs noted during a physical examination, and the results of diagnostic tests.

    There are many causes of both oropharyngeal dysphagia and esophageal dysphagia Table 01. Dysphagia is actually a symptom of an underlying condition. Because swallowing requires the healthy function of many different oral structures, muscles, and nerves, a wide range of different medical and dental conditions can cause dysphagia. Overall, oropharyngeal dysphagia is more common than esophageal dysphagia.

    Table 1.  Common Causes of Dysphagia

    Oropharyngeal dysphagia
    Parkinson?s disease
    Muscular dystrophy
    Tumors of the mouth or pharynx
    Drug-induced dry mouth (xerostomia)
    Radiation-induced dry mouth (xerostomia)
    Chemotherapy-induced inflammation of the mucosa of the mouth, ranging from redness to severe ulceration (mucositis).
    Esophageal dysphagia
    Inability to produce involuntary, wave-like contractions of esophagus (peristalsis), a condition know as achalasia?
    Esophageal spasms that block food and liquid instead of propelling them downward toward stomach (diffuse esophageal spasms)?
    Scleroderma: an autoimmune disease that can cause the weakening of tissues in the esophagus
    Age-related changes of motor function of esophagus
    Tumors of the esophagus
    Regions of narrowing (strictures)
    Lower esophageal ring that causes narrowing (Schatzki's ring)
    Pill-induced inflammation of the esophagus (pill esophagitis)?
    Esophagitis induced by gastroesophageal reflux disease (GERD)
    Functional (psychogenic) dysphagia: difficulty swallowing when no physical abnormalities are present; can be caused by stress

    Stroke is the most common cause of oropharyngeal dysphagia. Dysphagia can result from strokes that affect the area of the brain that controls motor actions (the cortex), and from strokes that affect the area of the brain that houses the swallowing center (the brain stem). About half of all stroke victims experience some degree of dysphagia in the post-stroke period, but in most of these cases, normal or near-normal swallowing function returns within one week.

    Esophageal dysphagia is most often due to actual blockages within the esophagus that are referred to as structural disorders. The disorders mechanically block food and liquid from moving towards the stomach. The most common structural problems are esophageal cancer, strictures, and lower esophageal rings (Schatzki's rings).

    • Esophageal cancer may cause dysphagia by narrowing the esophagus. This cancer most commonly occurs in older adults, and is often associated with rapid weight loss.
    • Strictures (narrowing of the esophagus) can be caused by any condition that causes severe acute injury, or chronic irritation of the esophageal lining. Gastroesophageal reflux disease (GERD) can lead to strictures; this condition is characterized by reflux of acidic stomach contents into the esophagus.
    • Schatzki’s rings (lower esophageal rings) are constrictive bands of connective tissue that occur in the inner wall of the lower esophagus. They are often associated with chronic reflux of the stomach contents. These rings usually don't produce symptoms unless they markedly narrow the esophagus.

    The conditions like achalasia or scleroderma can impair the normal, wave-like contractions of the esophagus (peristalsis) that propel food toward the stomach. Spasms of the esophagus can also interfere with peristalsis.

    • Achalasia is a disorder characterized by poor relaxation of the lower esophageal sphincter (LES) and loss of contractions of the esophageal muscle. As a result, food and liquids accumulate in the dilated esophagus.
    • Scleroderma is an autoimmune condition that can affect most organs and tissues of the body. Scleroderma can cause wasting of the esophageal muscle and poor contraction of the lower esophageal sphincter (LES). Dysphagia caused by scleroderma is often accompanied by heartburn.
    • Muscle spasms in the esophagus may occur spontaneously, and are often associated with chest pain. Instead of propelling swallowed food and liquid toward the stomach, these contractions block the movement of esophageal contents. In medical terms, these are referred to as diffuse esophageal spasms.

    Swallowing disorders in children are most commonly caused by structural conditions present at birth, and by disorders involving both the muscles and the nerves(neuromuscular conditions) such as muscular dystrophy.

    Many factors may contribute to dysphagia in older adults. Advancing age can be associated with poorly understood, age-related changes of esophageal motility. Many older adults also have dental problems and a generalized loss of muscle strength, and they may take a variety of drugs to treat specific medical conditions. All of these factors can contribute to dysphagia.

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