When swallowing, pain felt distinctly on only one side of the throat is medically termed unilateral odynophagia. While general throat infections often cause pain across the entire pharynx, this localized discomfort suggests a cause physically affecting one side more than the other. This asymmetrical presentation helps narrow the list of potential underlying issues. The symptom can range from a minor irritation to an indicator of a more serious, localized infection requiring professional attention.
Most Frequent Causes of Unilateral Pain
One of the most common origins of one-sided throat pain is an infection concentrated in a single tonsil or region of the pharynx. This manifests as unilateral tonsillitis or pharyngitis, where inflammation is significantly more pronounced on one side. Initial stages of bacterial infections, like Group A Streptococcus (strep throat), or many viral infections may begin causing localized pain before spreading.
The viral infection mononucleosis, caused by the Epstein-Barr virus, frequently leads to severe and asymmetrical swelling of the tonsils and surrounding lymph nodes. These swollen nodes, positioned along the neck, become tender and contribute to the one-sided pain felt upon swallowing. Post-nasal drip can also cause unilateral soreness. Excess mucus draining down the back of the throat may preferentially inflame one side, particularly if a person sleeps primarily on that side, allowing irritants to pool.
Structural and Non-Infectious Contributors
Non-infectious causes often involve a physical or chemical irritant localized to one area. Laryngopharyngeal reflux (LPR) or gastroesophageal reflux disease (GERD) occurs when stomach acid travels up the esophagus and irritates sensitive throat tissues. This pain can become unilateral due to sleeping position; if a person consistently sleeps on one side, the refluxed acid may pool and cause a chemical burn on that side of the pharyngeal lining.
Minor trauma can produce highly localized pain, such as a scratch from sharp food or irritation from a pill capsule that momentarily got stuck. A canker sore or small mouth ulcer on the tonsil or adjacent soft palate can create sharp, unilateral pain when swallowing. Another physical irritant is a tonsil stone (tonsillolith), a calcified collection of debris lodged in the tonsil’s small crevices. These hard deposits cause a foreign body sensation, persistent localized irritation, and referred pain to the ear on the affected side.
Symptoms Indicating Immediate Medical Attention
While most instances of unilateral throat pain are minor, certain accompanying symptoms signal a serious, rapidly progressing condition requiring immediate medical care. A peritonsillar abscess (PTA), a collection of pus forming behind one tonsil, is a serious complication of tonsillitis. Key indicators of PTA include trismus (difficulty opening the mouth fully), a muffled or “hot potato” voice, and extreme unilateral throat pain.
Any symptom indicating a compromised airway demands emergency attention. These include difficulty breathing, noisy breathing (stridor), or the inability to swallow saliva, leading to excessive drooling. Epiglottitis, the swelling of the epiglottis, is a life-threatening cause of airway obstruction that often starts with severe, one-sided throat pain. A rapid onset of high fever alongside neck swelling or the sudden inability to move the neck should also be treated as a medical emergency.
Home Care and Consulting a Healthcare Provider
For mild to moderate unilateral throat pain without emergency warning signs, several home care strategies can manage discomfort and support healing.
- Maintaining hydration helps thin mucus secretions and keeps the throat moist, reducing irritation.
- Gargling with warm salt water several times a day soothes inflammation and may assist in dislodging tonsil stones or clearing post-nasal drip.
- Over-the-counter pain relievers, such as acetaminophen or ibuprofen, reduce both pain and inflammation.
- Using a cool-mist humidifier, especially while sleeping, prevents the throat from drying out, which often worsens symptoms.
If the pain persists for more than three to five days, is accompanied by a fever that does not respond to medication, or worsens after initial home care, a professional diagnosis is warranted. A healthcare provider will perform a visual examination and may conduct a rapid test or culture to determine if a bacterial infection, such as strep throat, is the underlying cause.