The cheek and tongue
If the muscles on one side of the face are paralysed, food can accumulate between the cheek and the gums and may dribble out of the corner of the mouth. Difficulty in moving the tongue can interfere with movement of fluid or food to the back of the mouth.

The pharynx
Inflammation of the pharynx, such as a “sore throat”, can cause pain on swallowing.Disorders of the nerves or muscles which control the closure of the windpipe and back of the nose can lead to fluid or food entering the airway, and thus difficulty in swallowing. This may happen, for example, after a stroke or in the condition known as motor neurone disease. Rarely, a protrusion or pouch can develop from the wall of the pharynx into which fluid or food pass rather than proceeding onwards.

The gullet
Inflammation of the gullet may cause pain in the chest on swallowing.  Prolonged inflammation due to acid from the stomach entering the lower part of the gullet can lead to scarring and narrowing, known as a “benign” stricture. A cancer can also lead to narrowing and the tumour may bulge into the open channel of the gullet.

Occasionally, the gullet is blocked by a piece of bone or other solid object that has been swallowed by mistake.  A normal solid lump of food can be held up at a point of narrowing causing a sudden sense that the gullet is blocked.

Failure of the lower end of the gullet to relax and let the food through is an uncommon form of difficulty in swallowing known as achalasia.

What symptoms can be experienced?

Discomfort in the region of the “Adam’s Apple”
A sense of discomfort, described as a “lump” or tightness in the throat, in the region of the Adam’s Apple is common. The person feels that repeated swallowing is necessary to clear the discomfort, but in fact this does not help and may even aggravate the sensation.     

The characteristic of this discomfort is that it occurs between meals and the mechanism of swallowing is unaffected.   Usually, no abnormality is found on investigation.  Sometimes  acid reflux into the lower gullet may be shown, but the relation of this to the discomfort higher up is not clear.

“Food going down the wrong way”, coughing, spluttering, choking, or recurrent chest infections
These symptoms may occur if some food or fluid enters the windpipe rather than all passing into the gullet.   Dribbling from the mouth or attacks of coughing at night may indicate that the gullet or a pouch are not emptying properly so that the contents pass upwards on lying flat.

Pain or discomfort in the lower chest
Most people are familiar with discomfort experienced in the lower chest after swallowing a boiled sweet before it has dissolved.   A similar discomfort may occur after food if its passage is held up.  This discomfort is unlike the burning sensation associated with acid rising into the gullet after a meal.

A sense of blockage during a meal
If there is narrowing of the gullet, a sense that the food is held up or of blockage may be experienced after swallowing solid food such as lumps of bread or meat.   Should the narrowing become progressively worse, difficulty may then be experienced with liquids.   In contrast, failure of the lower end of the gullet to relax affects the passage of both liquids and solids from the onset of symptoms.