Swollen Throat – Causes of Throat (Pharynx) Swelling

The throat (technically referred to as the pharynx) is an important anatomical structure that serves as a common passage for food, water, and air. The food and drink consumed through the mouth enter the esophagus via the throat. The air that is inhaled through the nose also passes through the throat before entering the larynx, trachea and bronchi. Air exhaled from the lungs travels back through the throat before being passed out through the nose or the mouth. Therefore, the presence of any swelling in the throat can affect the movement of both food and air through it.

In some cases, the swelling in the throat may be severe enough to completely block the passage of food or air, resulting in a lethal scenario. This is especially worrisome when the swelling in the throat arises suddenly and is not attended to promptly. However, in most cases, the swelling develops gradually and does not cause any significant obstruction to the flow of air through the throat. A swollen throat is often accompanied by symptoms such as soreness or pain in the throat, hoarse voice, and difficulty in swallowing.

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Why does the throat swell?

The lining of the throat is similar to the lining of the digestive and respiratory tracts. Any injury or irritation of the lining of the throat can result in inflammation. An inflammatory reaction is characterized by exodus of fluid from the neighboring blood vessels into the tissues spaces. Red blood cells are not usually a part of the fluid that seeps out into the tissues spaces during inflammation.

Accumulation of this fluid in the tissue spaces causes swelling of the tissue. Inflammation is also characterized by redness, pain and heat in the affected tissue areas.  Swelling in the throat may not affect all parts of the throat. For example, a swollen throat can be caused by localized inflammation of the tonsillar tissue (tonsillitis), which leads to swelling of the tonsils.

In other cases, swelling in the throat may be due to the presence of a mass, such as a tumor or peritonsillar abscess. Not all cases of throat obstruction are caused by swelling in the throat. For example, obstruction of the passage through the throat can also be caused by the presence of an external mass that impinges on the walls of the throat.

Causes of Swollen Throat

Swelling in the throat is not the same as swelling in the neck. The throat (or pharynx) is located within the neck. However, the neck also contains other structures such as thyroid gland, blood vessels, muscles and nerves. One cannot easily identify a swollen throat by seeing or touching the neck area.

A swollen throat may result from a variety of causes. For example, the cause of a swollen throat may simply be an injury to the lining of the throat that was caused during brushing. Intake of certain foods may cause a rapid swelling of the throat, which may turn fatal if not treated promptly.

Not all causes of swelling in the throat reside within the throat. In some cases, the cause of a swollen throat may be located within the nasal cavity, mouth, airways or upper areas of the gut.


Inflammation of the throat (pharynx) and tonsils is technically referred to as pharyngotonsillitis. In everyday language, pharyngotonsillitis is referred to as a sore throat. A variety of factors can cause a sore throat. Examples include viral infections, bacterial infections, repeated bouts of vomiting, and inhalation of smoke. Common cold and strep throat are two of the most common causes of pharygotonsillitis or sore throat.

Post nasal drip

The mucus present in the nasal passages drains down the throat throughout the day. This is a normal process. However, when the mucus production is excessive (such as in allergies or cold), one may feel the mucus from the nasal passages dripping into the pharynx. This post nasal drip can cause irritation of the lining of the throat. Shallow coughing may follow in an attempt to clear the throat. This may cause further irritation in the throat.

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Goiter is a medical condition that is characterized by an enlargement of the thyroid gland in the neck. A variety of factors can lead to an enlargement of the thyroid gland. Some of the common causes include autoimmune diseases, inflammation, infection, and nodules. A swollen thyroid gland may cause a visible or palpable swelling in the neck. However, it rarely causes significant obstruction in the throat.


Anaphylaxis is a severe form of allergic reaction that can quickly turn fatal if not treated in time. The most common triggers of anaphylactic reactions are certain kinds of foods and drugs. Anaphylactic reaction occurs in individuals who are hypersensitive to certain allergens. The reaction occurs rapidly (within a few seconds or a few minutes) after consumption of the allergen. Difficulty in breathing due to swelling in the throat is a common symptom of an anaphylactic reaction.


Snoring is caused when air flow through the throat gets obstructed because of a collapse of the walls of the throat. The flow of air through such a collapsed or relaxed throat causes vibration of the walls of the throat, resulting in the snoring sounds. Snoring can lead to a variety of health complications. Heavy snorers typically complain of sore throat in the mornings.

Acid reflux

Acid reflux refers to regurgitation of gastric acid into the esophagus and the pharynx. The backward flow of gastric acid is prevented under normal circumstances by the lower esophageal sphincter (abbreviated as LES), which is present at the junction of the esophagus and the stomach.

A weakening of the lower esophageal sphincter can cause the gastric acid to flow backwards into the esophagus, and sometimes into the pharynx. The high acidity of the gastric acid damages the walls of the esophagus and the pharynx, resulting in inflammation and swelling.


The feeling of swelling in the throat may also be precipitated by certain emotional states such as anxiety. Such a feeling may also be accompanied by physical symptoms such as difficulty in breathing, heart palpitations, and pain in the chest.

Eating disorders

Individuals who have eating disorders often engage in unhealthy practices such as purging or inducing vomiting by sticking a finger or an object into the throat. This can cause injury to the lining of the throat, resulting in inflammation and swelling.

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