A throat sore, medically known as a pharyngeal or esophageal ulcer, is a painful lesion or open wound that develops on the mucous membranes lining the back of the throat, tonsils, or voice box (larynx). These sores cause significant discomfort, making swallowing, talking, and even breathing difficult. Causes for these lesions vary widely, encompassing contagious infections and chronic irritation.
Viral Origins of Throat Sores
Most infectious throat sores are triggered by common viruses. These pathogens directly invade the mucosal cells of the throat, leading to inflammation and the formation of visible lesions or ulcers. This group includes viruses responsible for the common cold, influenza, and COVID-19.
The Epstein-Barr virus (EBV) causes mononucleosis, often resulting in severely inflamed tonsils and throat sores. Enteroviruses, such as Coxsackievirus, cause Hand, Foot, and Mouth Disease and a related condition called herpangina. Herpangina is characterized by small, blister-like sores and ulcers that appear on the soft palate and the back of the throat, primarily affecting children.
Viral infections typically run their course, and the sores they cause heal on their own as the body’s immune system clears the pathogen. Because these infections are not caused by bacteria, they do not respond to antibiotic treatment. Symptoms often accompany other cold-like signs, such as a cough, runny nose, or general body aches.
Bacterial and Fungal Sources
While less frequent than viral causes in adults, bacterial infections can lead to painful throat sores that require targeted medical intervention. The most common bacterial culprit is Group A Streptococcus, which is the cause of strep throat. This infection can be distinguished from a viral sore throat by its sudden onset, the lack of a cough or runny nose, and the presence of white patches or pus on the tonsils.
Strep throat needs to be treated with antibiotics to prevent potential complications, such as rheumatic fever. Other bacterial causes, though less common, can include abscesses or severe tonsillitis that cause significant tissue breakdown. These bacterial sores are often intensely painful and may present with a high fever.
Fungal infections, most often oral candidiasis (thrush) caused by Candida yeast, are another microbial cause. This condition manifests as white, cottage cheese-like patches on the tongue, cheeks, and back of the throat, which can become painful and ulcerated. Oral thrush is most common in individuals with weakened immune systems, those using inhaled steroids, or people on long-term antibiotic therapy.
Non-Infectious Causes: Physical and Chemical Irritation
Not all throat sores are the result of an infection; many stem from direct physical or chemical damage to the delicate lining of the throat. One common source is mechanical trauma, which can occur from swallowing sharp or hard foods that scrape the pharyngeal wall. Medical procedures, like the insertion of a breathing tube during surgery (intubation), can also cause temporary ulcers or granulomas on the voice box.
Chemical irritation is frequently caused by the chronic backflow of stomach acid, known as gastroesophageal reflux disease (GERD) or laryngopharyngeal reflux (LPR). The acid irritates the pharynx and larynx, leading to persistent inflammation and ulcers. Smoking, vaping, and exposure to environmental irritants like smoke, dust, or chemicals can also directly damage the throat tissue, causing chronic soreness and lesions.
The overuse of the voice, such as prolonged shouting or singing, places excessive strain on the vocal cords, which can result in the formation of granulomas or ulcers on the larynx. Furthermore, continuously breathing through the mouth, often due to chronic nasal congestion or very dry indoor air, can dry out and scratch the throat lining, contributing to irritation and soreness.
Identifying Signs of Severe or Chronic Issues
While most throat sores resolve spontaneously, certain symptoms signal a potentially severe or chronic underlying condition requiring prompt medical evaluation. A sore that persists for longer than 10 to 14 days without improvement should be examined, especially if accompanied by unexplained weight loss or a lump in the neck.
Immediate medical attention is necessary if a sore throat is associated with difficulty breathing or extreme difficulty swallowing, which may indicate a rapidly progressing infection or airway obstruction. Other serious warning signs include a high fever above 102°F, a stiff neck, or the inability to open the mouth fully. Although rare, a persistent sore or ulcer can also be a manifestation of an autoimmune disorder or malignancy, particularly in individuals with a history of tobacco or excessive alcohol use.