Sores in the back of the throat are a common source of discomfort and concern. This area, known as the pharynx, is lined with sensitive mucous membranes that react to various internal and external factors. The specific appearance of the sore can offer clues about the underlying cause, which ranges from simple irritation to transmissible infections. This information is purely informational and should never replace a professional medical diagnosis.
Infectious Origins of Sores
Viral infections are the most common culprits, often presenting with symptoms like a cough, runny nose, and general body aches. Viruses causing the common cold or flu lead to a raw, irritated throat lining due to inflammation. A specific viral condition, herpangina, causes small, painful blisters to appear predominantly on the soft palate and tonsils. These blisters then break down into shallow ulcers and are usually caused by Coxsackie A viruses.
Bacterial infections, such as streptococcal pharyngitis (strep throat), are caused by the bacterium Streptococcus pyogenes, also known as Group A Streptococcus. The bacteria trigger an inflammatory response, often resulting in red, swollen tonsils that display white patches, spots, or streaks of pus. Unlike most viral infections, strep throat rarely presents with a cough or runny nose.
The fungus Candida albicans can cause sores in the throat known as oral thrush or candidiasis. This yeast is a normal part of the oral microbiota but can overgrow when the immune system is suppressed or after antibiotic use. Oral thrush typically appears as creamy white, slightly raised patches on the tongue, cheeks, or the back of the throat. These patches can often be scraped away, revealing a raw, red, and tender surface beneath.
Non-Infectious Causes and Irritants
One common source of irritation is the backflow of stomach contents, known as Laryngopharyngeal Reflux (LPR). When the upper esophageal sphincter fails, stomach acid and digestive enzymes travel up to the throat and voice box. These substances irritate the sensitive tissue, leading to inflammation or ulceration. This irritation is sometimes called “silent reflux” because it frequently occurs without the classic heartburn symptom associated with GERD.
Physical damage to the throat lining can cause non-infectious sores. This happens accidentally by swallowing sharp food that scratches the pharynx or by consuming liquids that are too hot, causing a thermal burn. Chronic exposure to environmental irritants also leads to persistent tissue damage. Smoking, vaping, or inhaling chemical fumes can directly injure the delicate mucosal lining of the throat.
Aphthous ulcers, often called canker sores, are not caused by a virus or bacteria. While their exact cause is not fully understood, these lesions are often linked to factors like stress, minor trauma, or nutritional deficiencies. These painful, shallow lesions can appear anywhere in the mouth or throat area. Additionally, the constant presence of extremely dry air, particularly during winter, can irritate the throat lining, leading to generalized soreness.
Visual Clues for Identifying the Type of Sore
White patches or pus on the tonsils often point toward an infection, but the exact appearance helps narrow the source. Strep throat patches are typically streaks of pus or small dots on the tonsils. In contrast, oral thrush patches are usually creamy, slightly raised, and resemble cottage cheese, often spreading across the tongue and back of the throat.
Small, distinct red bumps or blisters on the posterior throat, soft palate, or uvula are highly suggestive of certain viral infections, such as herpangina. These lesions begin as red spots that quickly develop into small, fluid-filled blisters. They then break into shallow, yellowish ulcers with a surrounding red rim. This clustering of small, blister-like sores is a distinguishing visual marker.
Generalized redness, a raw appearance, or an inflamed area without distinct white patches or blisters often suggests non-infectious irritation or a common viral infection. Throat tissue affected by LPR may appear raw due to chronic acid exposure, sometimes accompanied by a sensation of a lump in the throat. Classic ulcers, like canker sores, typically present as a painful, round lesion with a white or yellowish center and a sharply defined red border. Tiny red spots on the roof of the mouth, known as petechiae, are also a visual sign associated with strep throat.
When Immediate Medical Attention is Necessary
While most sores resolve on their own, certain symptoms warrant immediate professional evaluation. These symptoms can indicate a more serious complication, such as a deep tissue infection or an abscess.
- Difficulty breathing.
- Swallowing pain so severe it prevents the management of saliva or causes drooling.
- A high fever, especially one above 103 degrees Fahrenheit.
- An inability to fully open the mouth (trismus).
- Blood in your saliva or phlegm.
- A persistent sore that lasts longer than one week without improvement.
- The sudden onset of a muffled or “hot potato” voice.