Chronic Sore Throat – Causes, Symptoms of Persistent Sore Throat

A chronic sore throat (pharyngitis) is considered as any persistent throat irritation, itchiness or pain that lasts for more than 3 months. While a sore throat is usually thought of as pain, even slight irritation or itchiness of throat can cause a level of discomfort that may be described as ‘sore’ by a patient. Sometimes dysphagia may be mistaken for a sore throat although this is a difficulty with swallowing with no pain. At other times the pain or discomfort may be lower down the respiratory tract , like in the larynx, where it is described as a sore throat.

Causes and Symptoms

The causes of a chronic sore throat may be due to an infection, chemical or mechanical injuries or some other cause of persistent inflammation. Identifying the cause depends on the other signs and symptoms present, apart from the sore throat, as well as considering the patient’s medical history. At times, other diagnostic investigation may be required. This may include a neck x-ray, CT scan or laryngoscopy.

A chronic sore throat may be accompanied by other signs and symptoms :

Acid Reflux

Rising gastric acid, especially when lying flat, can inflame the tissues at the back of the throat.

  • Throat irritation in the morning, after sleeping.
  • History of gastroesophageal reflux disease (GERD).
  • Episodes of heartburn with nausea or regurgitation.
  • Condition improves after starting medication for GERD (antacids, H2-receptor blockers, proton pump inhibitors)


Smoking tobacco or narcotic substances and drinking alcohol can irritate the throat and lead to a persistent sore throat. In terms of a chronic sore throat, this is more often seen in addicts and abusers. These substances are abrasive to the epithelial lining of the mouth and throat and even the smoke may contain toxic chemicals that can cause inflammation of the mouth and respiratory passages.


Allergic reactions may cause angioedema* or trigger post-nasal drip which can irritate the throat.

  • Sneezing, nasal congestion or a runny nose, red eyes, itchy throat.
  • Severe cases may cause swelling of the airways leading to trouble breathing.
  • History of sinusitis, allergic rhinitis (hay fever), asthma or eczema.
  • Condition may aggravate after eating certain foods, insect bites, inhaling pollen or dust or during stress.

* Certain types of angioedema may not be a result of an allergic response.

Eating Disorders

Repeated vomiting which is induced in certain types of eating disorders, like bulimia, will cause irritation of the throat due to the action of the gastric acid. There may also be injury to the throat by using tools like the back of a toothbrush to induce vomiting.

  • Throat irritation after eating, vomiting.
  • Lack of appetite.
  • Compulsive behavior especially when it comes to food.
  • Comfort eating.
  • Obsession with body weight, size.

Foreign Objects

Foreign bodies that either lodge in the tonsils or tissue of the throat, like a fish bone, causes acute episodes of pain or even bleeding and medical treatment is usually sought. However, in some cases, a foreign body may be repeatedly introduced into the throat. For example : using the back of a toothbrush to induce vomiting in bulimia.

Some unusual practices may cause repeated injury and infection of the throat. This may include abnormal cravings like pica where a person eats sand or even feces. Certain sexual acts can also cause injury and introduce infectious agents into the mouth or throat area. This may cause repeated episodes of throat irritation and/or infection which may be reported as a chronic sore throat.


Most viral and bacterial infections that cause a sore throat are short lived. Either the body recovers from these infections, as is the case with the common cold or seasonal flu, or medical intervention becomes essential due to the progression of the condition, as with a strep throat.

In certain cases the nasopharynx may be prone to repeated infections which may be considered to be chronic in nature. In chronic sinusitis, there are repeated episodes of acute infections of the sinuses. This may also occur with post nasal drip. The infection in the nose or sinus can spread downwards toward the throat. In chronic tonsillitis, the tonsils are prone to repeated bacterial infections.

There are certain chronic infections associated with immunocompromised patients that may cause a persistent sore throat. The most common of these is oral thrush (candida or yeast infection) which starts on the tongue and spreads down the throat. It is common in HIV/AIDS patients or those with other chronic conditions like uncontrolled diabetes. White spots on the tongue or small whitish-yellow patches/plaques may be visible.

Mouth Breathing

The most common cause of mouth breathing is nasal congestion. The nasal cavity usually warms and moistens the air entering into the airways but in mouth breathing, this does not occur. The flow of air through the mouth and then into the throat may cause a dry mouth and throat. This can cause throat irritation and may result in a hoarse voice. Cold and dry environments as well as air conditioned building aggravate the condition. Some users of a CPAP machine may also experience this phenomenon.

Certain respiratory and cardiac conditions may lead to dyspnea (shortness of breath). With chronic causes of dyspnea, the person may begin to breathe through the mouth in an attempt to inhale more air. Some of the causes may include chronic obstructive pulmonary disease (COPD), lung cancer, or heart failure.


Pollutants in the air, drinking water or even food may cause a chronic sore throat. Polluted air, especially in industrial areas, are a common cause of sore throat and may be accompanied by burning eyes and aggravation of allergies. At times, the pollutants may be placed in the food and water as part of intentional poisoning. This may be followed by stomach cramps, difficulty breathing, nausea, vomiting or diarrhea.


The back of the palate is the soft palate which is flexible. In a person who snores this part of the palate moves excessively during sleep and this can cause localized inflammation. A person who snores also tends to draw air through the mouth (mouth breathing) and this can irritate the epithelial tissue and even the muscles of the throat.

  • Throat irritation after sleeping.
  • Person or partner reports snorning.
  • Person may feel tired after sleeping.
  • Voice may be slightly hoarse for a few hours after awakening.
  • Disturbed sleep in cases of sleep apnea.


In chronic tonsillitis, the tonsils are constantly inflamed. This inflammation leads to pain and the tonsils are prone to repeated bouts of infections. There may be pain upon swallowing, a constant need to clear the throat and episodes of coughing up food. A tonsillectomy is necessary in these cases.

Thyroid Gland

Inflammation of the thyroid gland (thyroiditis) or an enlarged thyroid gland (goiter) may cause discomfort or even pain which may be reported as a sore throat. There may be no signs or symptoms of hypothyroidism or hyperthyroidism


Any tumor towards the back of the mouth, in the throat and larynx may be described as a sore throat. Pain may be present or the person can feel a ‘lump in the throat’. This should not be confused with a globus sensation where there is the sensation of a lump in the throat but there is no actual physical cause.

Voice Strain

Excessive or loud talking and shouting, especially if it is part of a person’s occupation or daily habit, may result in a chronic sore throat. Nodules may form on the vocal cords and while this may not cause any pain, a person with these nodules will have to strain to talk and shout, further irritating the throat. Any vocal strain may also cause irritation of the the area around the hyoid bone which may be felt as discomfort at the upper part of throat. Signs and symptoms associated with a vocal strain may include :

  • Hoarseness or loss of voice.
  • Pain upon speaking, even whispering.
  • Persistent dry mouth.
  • Occupation where constant talking or shouting is necessary.

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