A sore throat that hurts on just one side usually points to a localized process rather than a widespread infection like a common cold. The cause can range from something as benign as a tonsil stone to something as urgent as an abscess or, in rare cases, a cancer. That asymmetry is actually a useful clue, because it narrows the list of likely explanations and can guide you and your doctor toward the right diagnosis faster than a vague bilateral soreness would.
Peritonsillar Abscess
If your one-sided sore throat came on quickly, feels severe, and makes it hard to open your mouth, the most likely serious cause is a peritonsillar abscess. This is a pocket of pus that forms in the tissue just behind one tonsil, almost always on one side only. It typically develops as a complication of tonsillitis or strep throat when the infection burrows into the soft tissue surrounding the tonsil.
A hallmark feature is trismus, the medical term for difficulty opening your jaw. In a prospective study of 100 consecutive peritonsillar infections, trismus, deviation of the uvula toward the opposite side, and bulging of the front pillar of the tonsil were all strongly associated with abscess rather than simple cellulitis.1ScienceDirect. Peritonsillar Infections: Prospective Study of 100 Consecutive Cases You may also notice a muffled “hot potato” voice, drooling, or ear pain on the same side. Treatment usually involves draining the abscess, intravenous antibiotics, and sometimes a short course of steroids to reduce swelling. This is not something you can ride out at home with lozenges.
Tonsil Stones
Tonsil stones, or tonsilloliths, are small, calcified deposits that form in the crevices of the tonsils. They are extremely common, often go unnoticed, and by themselves are harmless. But when one gets large enough or sits in a spot that irritates the surrounding tissue, it can cause a persistent sore throat on one side, along with bad breath and a nagging foreign-body sensation.
Smaller tonsil stones tend to cause recurring mild sore throats and halitosis.2Journal of the Scientific Society. A Giant Tonsillolith: An Unusual Cause for Longstanding Foreign Body Sensation in Throat Occasionally, they grow surprisingly large. One reported case involved a stone measuring over 3 centimeters across, found in a man who had experienced recurrent sore throats for years.3PubMed Central. A giant tonsillolith Most tonsil stones can be dislodged at home with gentle pressure or a water irrigator. If they keep coming back and the sore throats are bothersome, an ENT specialist can discuss whether tonsillectomy makes sense.
Wisdom Teeth and Pericoronitis
The back of your mouth is surprisingly interconnected. An impacted or partially erupted wisdom tooth can cause inflammation of the gum tissue surrounding it, a condition called pericoronitis, and that pain frequently radiates upward into the throat on the same side. Many people don’t make the connection because they think of dental pain and throat pain as separate problems.
Research has found a strong association between pericoronitis and respiratory tract infections, with the risk of an upper respiratory infection peaking in the days just before a pericoronitis flare-up.4BMJ. Respiratory tract infections and concomitant pericoronitis of the wisdom teeth This means that when you get a cold, your wisdom-tooth area may flare simultaneously, creating a one-sided sore throat that seems disproportionate to your other cold symptoms. If your sore throat tends to come back on the same side and you still have your wisdom teeth, a dental exam and a panoramic X-ray can settle the question.
Something Stuck in the Throat
A foreign body lodged in the throat or upper esophagus can produce intense one-sided pain, especially during swallowing. Fish bones are one of the most frequent culprits in emergency departments. The typical presentation is a sharp pain that began during a meal and did not go away afterward.5PubMed Central. Migratory Fish Bone in the Thyroid Gland: Case Report and Literature Review
What makes foreign bodies tricky is that the pain can persist long after the object has either passed or embedded itself in the soft tissue. In one case, a fish bone that a patient swallowed while eating Atlantic cod was found a week later lodged in the soft tissue on one side of the neck, between the throat and the spine.6Polski Przegląd Otorynolaryngologiczny. A foreign body (a fish bone) in the esophagus translocating into soft tissues of the neck – a case report If you ate fish or chicken with small bones and developed sudden one-sided throat pain during or shortly after the meal, don’t dismiss it. A CT scan or a simple look with a laryngoscope can identify the problem before it migrates deeper.
Subacute Thyroiditis Pretending to Be a Sore Throat
This one catches both patients and doctors off guard. Subacute thyroiditis is inflammation of the thyroid gland, usually triggered by a viral infection, and it can present as one-sided throat pain that responds poorly to the usual sore-throat treatments. Because the thyroid sits low in the front of the neck, it is rarely the first thing anyone suspects when the complaint is throat pain.
A recent case series documented 32 patients whose primary symptom was one-sided throat pain, all of whom were eventually diagnosed with subacute thyroiditis. These patients, mostly women between the ages of 28 and 52, had been experiencing the pain for anywhere from a week to three months before the correct diagnosis was reached. Nineteen reported left-sided pain, thirteen reported right-sided pain.7PubMed Central. Unilateral pharyngalgia as the dominant symptom in subacute thyroiditis: Case series and analysis of diagnostic pitfalls in clinical practice The diagnostic delay happened because clinicians were treating for pharyngitis or tonsillitis while the real culprit sat an inch or two lower. A simple thyroid function blood test and thyroid ultrasound can catch it.
The reason this matters practically is that subacute thyroiditis is self-limiting, it usually resolves in weeks to a few months, but it may briefly cause hyperthyroidism followed by a phase of hypothyroidism. Anti-inflammatory medications are the typical treatment, and antibiotics do nothing because the inflammation is not bacterial.
Glossopharyngeal Neuralgia
Some one-sided throat pain has nothing to do with infection or anatomy and everything to do with a misfiring nerve. Glossopharyngeal neuralgia is a rare condition that produces sudden, severe, stabbing episodes of pain at the base of the tongue, the tonsil, or the area beneath the angle of the jaw, almost always on one side.8PubMed Central. An uncommonly common: Glossopharyngeal neuralgia The pain can also radiate into the ear. It tends to be triggered by swallowing, talking, coughing, or yawning.
The episodes are brief, lasting seconds to a couple of minutes, but they can be excruciating. The underlying mechanism often involves a blood vessel, typically a branch of the cerebellar artery, pressing against the glossopharyngeal nerve where it exits the brainstem.9PubMed Central. Glossopharyngeal neuralgia caused by a complex neurovascular conflict: Case report and review of the literature Treatment usually starts with medications used for nerve pain. In cases that don’t respond, surgery to relieve the pressure on the nerve can be effective.
If you’re experiencing brief but intense jolts of one-sided throat or ear pain with pain-free intervals in between, that pattern is a strong hint toward neuralgia rather than an infection. Infections produce steady or gradually worsening pain, not lightning-bolt episodes.
Eagle’s Syndrome
Just behind each tonsil, a small, pointed bone called the styloid process extends downward from the base of the skull. In some people, this bone is longer than normal or the ligament connecting it to the small bone in the throat becomes calcified. When that happens, the elongated structure can poke into or compress surrounding tissues, producing recurring throat pain, a feeling that something is stuck in the throat, or pain with swallowing, almost always on the affected side.10The Saudi Dental Journal. Eagle’s syndrome – A case report and review of the literature
Eagle’s syndrome is uncommon, but it is probably underdiagnosed because the symptoms overlap with so many other conditions. It can mimic peritonsillar abscess, glossopharyngeal neuralgia, or even temporomandibular joint disorders. A CT scan that captures the length and angle of the styloid process is usually what clinches the diagnosis. In rare cases, an elongated styloid can press against the carotid artery, which could theoretically contribute to arterial damage.11PubMed Central. Carotid artery dissection: a rare complication of Eagle syndrome Surgical shortening of the styloid process is the definitive treatment when symptoms are persistent.
Lemierre’s Syndrome and Deep Neck Infections
Lemierre’s syndrome is rare and serious. It begins as a bacterial throat infection, most often caused by a bacterium called Fusobacterium necrophorum, and then spreads into the spaces surrounding the throat. The infection reaches the internal jugular vein, the large vein running down the side of the neck, and causes a clot to form inside it.12PubMed Central. Lemierre’s Syndrome From there, infected clot fragments can break off and travel to the lungs and other organs.
The classic scenario involves a young person who had a sore throat, seemed to improve, and then got much worse, often with a stiff, swollen, painful neck on one side, high fever, and signs of spreading infection. One reported case involved a 17-year-old who came to the emergency department with persistent one-sided sore throat, fever, and right-sided neck pain despite having been on antibiotics.13Emergency Care Journal. From a sore throat to Lemierre syndrome. A case report and literature review Imaging revealed a blood clot in a vein on the right side of his neck and septic emboli throughout his body.
Lemierre’s syndrome is sometimes called the “forgotten disease” because antibiotics made it so rare that many clinicians have never seen a case. The critical warning sign is a sore throat that initially improves and then rebounds dramatically with neck swelling and fever. That pattern, especially in a teenager or young adult, warrants urgent imaging of the neck veins.
Oropharyngeal Cancer
This is the cause nobody wants to think about, but it belongs in the conversation for anyone whose one-sided sore throat has been present for weeks without an obvious explanation. Cancers of the oropharynx, the area that includes the tonsils and the base of the tongue, frequently produce unilateral symptoms because the tumor typically starts on one side.
A study of patients with oropharyngeal squamous cell cancer found that sore throat and a neck mass were the two most common initial symptoms, with about a third of patients reporting sore throat as what first brought them in for evaluation. Interestingly, patients whose tumors were HPV-negative were more likely to initially notice the sore throat, while HPV-positive patients were more likely to first discover a painless lump in the neck.14JAMA Otolaryngology–Head & Neck Surgery. Initial Symptoms in Patients With HPV-Positive and HPV-Negative Oropharyngeal Cancer
The red flags that should prompt a thorough evaluation include a one-sided sore throat lasting more than two to three weeks, unexplained weight loss, difficulty swallowing that seems to be getting worse, a persistent lump in the neck, ear pain on the same side without an ear infection, or a change in voice. Any one of these in isolation may have a harmless explanation, but the combination of persistent unilateral throat pain with another red flag warrants a visit to an ENT specialist, who can examine the throat directly with a flexible camera.
Unilateral Supraglottitis
Epiglottitis, more broadly called supraglottitis, is an inflammation of the tissue above the vocal cords that can swell enough to compromise the airway. While the classic childhood form has become rare thanks to the Hib vaccine, it still occurs in adults, with an estimated incidence of roughly one to two cases per 100,000 adults per year.15Visual Journal of Emergency Medicine. Unilateral supraglottitis – A rare cause of sore throat Adult supraglottitis can sometimes be one-sided, presenting as severe unilateral sore throat with pain out of proportion to what the doctor sees when looking at the back of the throat with a tongue depressor. The key danger is airway compromise: if the swelling progresses, it can obstruct breathing. Drooling, a preference for sitting upright and leaning forward, and a muffled voice should prompt immediate emergency evaluation.
After Surgery or Intubation
If your one-sided sore throat started after a surgery that required general anesthesia, the most likely explanation is mechanical irritation from the breathing tube. During intubation, the tube passes through the mouth and between the vocal cords, and the mucous membrane lining the throat can sustain minor damage on one side more than the other, depending on the angle of insertion and the anatomy of the patient’s airway.16PubMed Central. Postoperative Sore Throat After Tracheal Intubation: An Updated Narrative Review and Call for Action This type of sore throat typically resolves within a few days. If it persists beyond a week, or if you notice a change in your voice or difficulty swallowing, follow up with your doctor.
Less Common Mimics
A handful of other conditions can produce one-sided throat pain without fitting neatly into the categories above. Relapsing polychondritis, an autoimmune condition that attacks cartilage throughout the body, has been reported to initially present as a persistent sore throat misdiagnosed as chronic pharyngitis.17PubMed Central. Relapsing polychondritis: an unusual cause of sore throat, painful ear swelling and bilateral costal margin pain In that context, the sore throat doesn’t respond to antibiotics and is often accompanied by other cartilage-related symptoms like ear swelling or rib pain. Carotidynia, inflammation of the carotid artery, can refer pain to the throat on one side, though this is an uncommon diagnosis typically made after other causes have been excluded.
When to Seek Urgent Care
Most one-sided sore throats are caused by the same viruses and bacteria that cause any sore throat, with the asymmetry reflecting a tonsil or lymph node that happened to get hit harder on one side. Those will resolve on their own or with standard treatment. But certain features should change your timeline from “wait and see” to “get evaluated soon or immediately.”
Go to an emergency department if you experience any of the following alongside your one-sided sore throat:
- Difficulty breathing: any sensation that your airway is narrowing, stridor (a high-pitched sound when breathing in), or inability to swallow your own saliva.
- Inability to open your mouth: significant trismus suggests a peritonsillar abscess or deep space infection.
- Rapidly spreading neck swelling: especially with fever, this can indicate a deep neck abscess, which specialists in otorhinolaryngology consider a potentially life-threatening emergency requiring surgical drainage.18PubMed Central. Emergencies in Otorhinolaryngology: Diagnostic Evaluation, Assessment of Urgency, and Treatment
- Rebound illness: a sore throat that improved and then worsened dramatically with high fever and neck pain, which is the pattern associated with Lemierre’s syndrome.
See a doctor within a few days if your one-sided sore throat has lasted more than a week without improving, if you have a persistent lump in the neck, if you notice unexplained ear pain on the same side, or if you are losing weight without trying. These features do not mean something dangerous is happening, but they do mean the list of possible causes includes conditions that benefit from early diagnosis.
For the garden-variety one-sided sore throat that comes with a cold, you can treat it the same way you would any sore throat: stay hydrated, use over-the-counter pain relievers, and try warm salt-water gargles. If it hasn’t improved after about five days, or if it worsens at any point, check in with your doctor to make sure something else isn’t going on.