Pain on just one side of the back of your throat usually points to a localized issue rather than a widespread infection. While most sore throats affect both sides equally, one-sided pain narrows the list of likely causes to problems that are physically concentrated in one spot: an inflamed tonsil, a developing abscess, a swollen lymph node, or even a dental problem radiating pain into the throat.
Infections That Hit One Side Harder
Viruses are the most common cause of sore throats overall, but viral infections typically produce pain across the entire throat. When only one side hurts, a bacterial infection is more likely to blame. Strep throat, for example, can sometimes inflame one tonsil more than the other, especially early on. Tonsillitis from any cause can be asymmetric, with one tonsil becoming more swollen and painful than its partner.
Mononucleosis (caused by the Epstein-Barr virus) is another possibility, particularly in teens and young adults. It can cause significant tonsil swelling that’s worse on one side, along with fatigue and swollen glands in the neck.
Peritonsillar Abscess
If one-sided throat pain is severe and getting worse over several days, a peritonsillar abscess is a serious possibility. This happens when a pocket of pus forms in the tissue next to a tonsil, usually as a complication of untreated tonsillitis or strep throat. It’s one of the most common deep infections of the head and neck.
The hallmarks are distinctive. You’ll likely have difficulty opening your mouth because the muscles around the jaw become inflamed and spasm. Your voice may sound muffled or thick, sometimes called a “hot potato” voice. Looking in a mirror, you might notice the soft palate on the affected side is red and bulging, and the uvula (the small tissue hanging at the back of your throat) may be pushed to the opposite side. The pain is typically intense enough that swallowing becomes very difficult, and it’s almost always worse on just one side. This needs medical attention promptly, as it won’t resolve on its own and can obstruct breathing if it grows large enough.
Tonsil Stones
Not everything that hurts on one side is an infection. Tonsil stones are small, hardened lumps made of calcium, food debris, and bacteria that form in the folds of your tonsils. They look like tiny white or yellow pebbles and can develop on just one side. Many people with tonsil stones describe a persistent feeling that something is stuck in the throat, along with bad breath and mild discomfort when swallowing. Small stones often cause only minor irritation, but larger ones can cause noticeable swelling and make swallowing uncomfortable. You can sometimes see them by looking in the back of your throat with a flashlight.
Swollen Lymph Nodes
The lymph nodes in your neck act as filters that trap viruses and bacteria before they spread further. When you’re fighting an infection, even a minor one like a cold or ear infection, the lymph nodes on the affected side can swell and become tender. Because the neck has lymph nodes on both sides, swelling on just one side can create the sensation that your throat hurts asymmetrically. You might feel a tender lump along the side of your neck or just below the jaw. Swollen nodes from common infections are usually soft, movable, and shrink back down within a couple of weeks as the infection clears.
Wisdom Teeth and Dental Problems
Your lower wisdom teeth sit remarkably close to your throat. When a wisdom tooth is erupting, impacted, or infected, the inflammation can spread to nearby tissues and feel exactly like a one-sided sore throat. An infected lower molar can trigger swelling in the surrounding lymph nodes, irritate the tonsil on that side, and send pain radiating into the ear, neck, and jaw. This overlap makes diagnosis tricky: what feels like a throat infection might actually be a dental abscess tracking through the soft tissue toward the throat. If your one-sided throat pain lines up with jaw tenderness, pain when biting down, or a visible problem with a back tooth, a dentist may be the right first call.
Acid Reflux Reaching the Throat
Acid reflux doesn’t always stop at the chest. In some people, stomach acid travels all the way up into the throat, a condition called laryngopharyngeal reflux. This tends to happen at night while you’re lying down and can cause a sore, raw feeling in the throat by morning. It may feel one-sided depending on your sleeping position. Sleeping on your left side positions the valve between your stomach and esophagus above the level of your stomach contents, which helps prevent reflux. Lying on your right side or back submerges that valve, making reflux more likely. If you consistently sleep on your right side, acid exposure could be concentrated on one part of your throat, leading to asymmetric irritation.
Nerve Pain in the Throat
Glossopharyngeal neuralgia is rare, but it produces a very recognizable pattern. It causes sudden, severe, stabbing pain in the tongue, throat, ear, or tonsil area, nearly always on just one side. Episodes last seconds to minutes and can strike many times a day. They’re often triggered by specific actions: swallowing, coughing, laughing, yawning, or drinking cold beverages. Some people find that even touching the tonsil area on the affected side sets off an episode. The pain can be intense enough to wake you from sleep. If your one-sided throat pain comes in sharp, brief bursts tied to swallowing or speaking, this is worth discussing with a doctor.
A separate but related condition, Eagle syndrome, occurs when a small bone beneath the skull (the styloid process) is abnormally long and presses on surrounding tissues. Most people with this condition have elongation on both sides, but pain typically shows up on only one. It can feel like something is permanently stuck in your throat, and it worsens with chewing, yawning, or turning your head. Pain often radiates to the ear and neck.
How Doctors Figure Out the Cause
If your one-sided throat pain doesn’t improve within a few days, a healthcare provider will start with a physical exam, looking at both tonsils, checking for asymmetric swelling, and feeling the lymph nodes in your neck. A rapid strep test can return results in minutes using a simple throat swab. If that’s negative but strep is still suspected, a throat culture sent to a lab gives more reliable results within 24 to 48 hours.
For deeper concerns, like a suspected abscess or structural problem, imaging comes into play. A CT scan can reveal a peritonsillar abscess, an elongated styloid process, or other abnormalities that a physical exam alone might miss. In some cases, a provider will use a small camera to look at the throat and vocal cords directly.
Signs That Need Immediate Attention
Most one-sided throat pain resolves on its own or with straightforward treatment. But certain symptoms signal that something more dangerous is happening. Difficulty breathing, inability to swallow liquids, excessive drooling (especially in children), or swollen glands severe enough to visibly distort the neck all warrant an emergency visit. Inability to open your mouth, a rapidly worsening “hot potato” voice, or a high fever alongside severe one-sided pain also point to conditions like a peritonsillar abscess that need urgent drainage. In children specifically, watch for irritability combined with an inability to move the neck, as this can indicate a deep neck infection.