Sore Throat on One Side Only: Causes and When to Worry

What causes pain on only one side of the throat?

Unlike strep throat or viral pharyngitis, which typically cause symmetric pain on both sides, one-sided throat pain tends to reflect a localized problem. The most common causes include:

• Peritonsillar abscess (quinsy) — a collection of pus beside one tonsil; the most serious cause of unilateral throat pain that requires urgent evaluation
• Tonsillitis or tonsillar infection involving one side more than the other — strep throat can sometimes appear more asymmetric 4Ref 4Mitchell RB, Archer SM, Ishman SL, Rosenfeld RM, Coles S, Finestone SA, et al. (2019).Clinical Practice Guideline: Tonsillectomy in Children (Update).Recurrent tonsillitis criteria and role of tonsillectomy; context for recurrent or persistent unilateral tonsillar disease and referral thresholds
• Swollen lymph node on one side of the neck that refers pain to the throat
• Minor trauma or irritation — a scratch from food, excessive throat-clearing, postnasal drip pooling on one side, or sleeping in a particular position
• Dental or jaw problem — an abscessed upper or lower molar or wisdom tooth can cause referred pain felt in the throat on that side
• Epiglottitis — rare but serious inflammation of the epiglottis; causes severe throat pain, drooling, and difficulty breathing
• Tonsil stone (tonsillolith) — calcified debris in a tonsil crypt; causes a sense of something stuck and localized discomfort but is not dangerous
• Post-nasal drip — mucus pooling preferentially to one side during sleep causing a raw, sore feeling on waking

What is a peritonsillar abscess and how do I recognize it?

A peritonsillar abscess is a collection of pus that forms in the tissue next to the tonsil, almost always on one side. It is the most common deep neck space infection in adults and adolescents 1Ref 1Powell J, Wilson JA (2012).An evidence-based review of peritonsillar abscess.Evidence-based review of peritonsillar abscess: it is the most common deep neck space infection in adults and adolescents; classic clinical features (trismus, hot-potato voice, uvular deviation, dysphagia); drainage (needle aspiration or incision) as definitive treatment2Ref 2Krishnaprasadh D, Hohman MH, McDowell RH (2026).Peritonsillar Abscess.Comprehensive clinical overview: epidemiology, pathophysiology, diagnosis, management, and complications of peritonsillar abscess — airway compromise risk if untreated; antibiotic therapy alongside drainage.

Recognizing it matters because it requires same-day medical attention 2Ref 2Krishnaprasadh D, Hohman MH, McDowell RH (2026).Peritonsillar Abscess.Comprehensive clinical overview: epidemiology, pathophysiology, diagnosis, management, and complications of peritonsillar abscess — airway compromise risk if untreated; antibiotic therapy alongside drainage — it does not resolve on its own and can compromise the airway if allowed to progress.

Classic signs of peritonsillar abscess include:

• Severe, worsening one-sided throat pain — often worse than any sore throat you have had before
• Difficulty swallowing — even saliva may become difficult to swallow
• Drooling — because swallowing is too painful
• Muffled, "hot potato" voice — a distinctive change in speech quality as if you have a potato in your mouth
• Trismus — difficulty opening the mouth fully due to spasm of the jaw muscles
• The tonsil on the affected side appears pushed toward the midline with the uvula (the soft hanging tissue at the back of the mouth) deviated toward the opposite side
• Fever and a feeling of being quite ill
• Enlarged, tender lymph node on that side of the neck

If several of these are present together, do not wait to see if it improves.

What other serious causes of one-sided throat pain should be on my radar?

Epiglottitis: Inflammation of the epiglottis (the flap at the top of the airway) can cause one-sided or midline severe throat pain with drooling, a muffled voice, and extreme difficulty breathing. This is an airway emergency. In adults, it can develop from bacterial infection; in children (though now rare with Hib vaccination) it can progress rapidly.

Parapharyngeal or retropharyngeal abscess: Deeper space infections can develop from a peritonsillar abscess that has spread or from a dental infection. These are surgical emergencies.

Malignancy: A persistent one-sided mass or ulceration in the tonsil area that does not improve over several weeks — especially in someone with a history of tobacco or alcohol use — warrants evaluation. Oropharyngeal cancers can sometimes present as one-sided tonsil swelling or pain.

Glossopharyngeal neuralgia: A less common cause — sharp, shooting pain in the throat, usually one-sided, triggered by swallowing or talking. This is a neurological condition requiring specialist evaluation.

When can I manage one-sided throat pain at home?

Mild, one-sided throat soreness without fever, without difficulty swallowing, and without the classic signs of a peritonsillar abscess can often be observed for 24–48 hours with:

• Warm saltwater gargles to soothe the mucosa
• Over-the-counter pain relief (ibuprofen or acetaminophen, taken as directed)
• Adequate hydration — staying well hydrated prevents the throat from becoming more irritated
• Checking the back of the throat with a light and mirror — if you can see a tonsil stone (small white or yellowish lump in the tonsil pocket), that may be the cause

If the pain is worsening, spreading, or accompanied by any of the serious features described above, the 24-48 hour wait is not appropriate — seek care promptly.

What will a doctor do for one-sided throat pain?

A clinician will examine the throat carefully, looking at symmetry of the tonsils and uvula, assessing for fluctuance (feeling of fluid under tissue) that suggests an abscess, and feeling the neck for lymph nodes.

• If a peritonsillar abscess is suspected or confirmed, treatment involves drainage (needle aspiration or incision) and antibiotics — this is done in an office or emergency department and provides immediate relief
• If strep throat is the cause, a rapid strep test or clinical scoring system helps confirm diagnosis 3Ref 3Linder JA, Watson ME, Wessels MR, et al. (2025).2025 Clinical Practice Guideline Update by the Infectious Diseases Society of America on Group A Streptococcal (GAS) Pharyngitis: Risk Assessment Using Clinical Scoring Systems in Children and Adults.2025 IDSA guideline update: clinical scoring systems to guide testing for group A streptococcal pharyngitis — relevant to the differential of one-sided tonsil infection vs peritonsillar abscess and penicillin (or an alternative) is prescribed
• If a dental abscess seems to be referring pain, referral to a dentist is appropriate
• If the cause is unclear or there is concern for deeper infection or mass, imaging (CT scan) or ENT referral may follow

A Gale primary care clinician can evaluate your throat pain, determine the most likely cause, and direct you to the right care — including same-day urgent assessment if needed.