Swallowing

Swallowing allows people to eat and drink, thus providing nutrients for growth and maintenance of body tissue. Saliva is regularly swallowed while awake and during sleep. Though swallowing usually occurs automatically, it involves a complex sequence of nerve and muscle coordination managed by the brain.

Normally, food and drink are formed into a mass by the mouth and channeled by the tongue to the back of the mouth, where the swallow is triggered. The pharynx and larynx, which are situated at the top of the esophagus (foodpipe) and trachea (windpipe), contract and elevate to protect the trachea. This is essential to prevent choking and inhalation of foreign substances. The mass is rapidly pushed through the pharynx into the esophagus, and then by coordinated muscular contractions to the stomach. Any disruption to this sequence can result in swallowing difficulties (technically known as dysphagia).

In the healthy adult noticeable swallowing difficulties are rare. However, changes associated with aging can affect the efficiency of the muscles that facilitate swallowing. As a result of these normal variations, some elderly people may be predisposed to dysphagia when they are ill. The likelihood of some illnesses increases with age, and a number of medical conditions are associated with dysphagia.

A common example is stroke. In the early stages of stroke, approximately half of those affected may develop dysphagia. Prevention of choking and consequent chest infection is a high priority. Fortunately, only a few stroke patients have persistent problems and recovery is common, even at advanced age. Other diseases develop more gradually (e.g., Parkinson’s disease and the various types of dementia). Eating and drinking can be slow and effortful procedures that deteriorate progressively. The consistencies of food and drink that can be swallowed easily and safely become more limited over time. Sometimes the first signs of a disease are difficulties with speech and swallowing (e.g., in amyotrophic lateral sclerosis or myasthenia gravis). Chronic illness affecting the breathing muscles can interrupt the fine coordination between breathing and swallowing, contributing to recurrent chest infections. Any severe illness can lead to generalized muscle weakness and consequent dysphagia, though this is usually a temporary effect.

Mechanical problems may also be a source of swallowing difficulty. Elderly people are more prone to osteophytes. These are bony growths from the spine and may push into the throat muscles causing coughing or discomfort when food or drink pass over the misshapen area. Another example is the development of a pouch (like a small pocket) in the pharynx or upper esophagus, impeding the smooth progression of the food or fluid mass to the stomach. Infections (such as thrush) can cause painful swallowing. Surgical procedures to any area related to the swallowing anatomy can also result in swallowing difficulties. A sensation of something sticking in the throat is often reported. This may be due to organic disease of the esophagus or stomach. If no physical cause is found, the reason may be psychological.

In many conditions the swallowing either improves spontaneously or strategies are used to make swallowing easier. If effective swallowing is impossible to achieve, then it may be necessary to consider feeding via a tube. This can be used temporarily or for a long period.