Allergies, infections, and illnesses can cause just one side of the throat to hurt. But if the pain is severe or accompanied by concerning symptoms, it may be an early indicator of a more serious condition.

Sore throats can range from irritating to excruciating. You’ve probably had a sore throat many times before, so you know what to expect. But what about pain on only one side of your throat?

Many things can cause a sore throat on one side, even if you don’t have tonsils. These include postnasal drip, canker sores, tooth infections, and other conditions. You might only have throat pain, or you might have additional symptoms, such as an earache.

Keep reading to learn more what might be causing your throat pain on one side.

Postnasal drip refers to mucus that drips down the back of your nose. When this happens, it might feel like all of that mucus is collecting in your throat.

Glands in your nose and throat regularly produce 1 to 2 quarts of mucus a day. However, if you’re sick with an infection or have allergies, you tend to produce more mucus. When the extra mucus accumulates and can’t drain properly, the feeling of it dripping down your throat may be uncomfortable.

Postnasal drip often irritates your throat, making it sore. You may feel this pain on only one side, especially in the morning after you’ve been sleeping on your side. Treatment for postnasal drip involves treating the underlying condition. In the meantime, you can take a decongestant, such as pseudoephedrine (Sudafed), for symptom relief.

Tonsillitis is inflammation, usually due to infection, of your tonsils. The tonsils are round balls of lymphatic tissue in the back of your throat. You have two tonsils, one on each side of your throat, just behind your tongue. Sometimes tonsillitis only affects one tonsil, creating a sore throat on one side.

Tonsillitis is usually caused by a viral infection, but bacterial infections can cause it as well. The primary symptom is a sore throat, usually accompanied by some of the following symptoms:

  • fever
  • bad breath
  • nasal congestion and runny nose
  • swollen lymph nodes
  • red, swollen tonsils covered with patches of pus
  • difficulty swallowing
  • headache
  • abdominal pain
  • raw, bleeding patches on the tonsils

Most cases of viral tonsillitis clear up on their own within 10 days. You can ease the pain with over-the-counter (OTC) pain relievers or home remedies, such as gargling with salt water.

If you have bacterial tonsillitis, you’ll likely need an antibiotic from your doctor.

A peritonsillar abscess is an infection that creates a walled-off collection of pus adjacent to, and often behind, one of your tonsils. It usually begins as a complication of bacterial tonsillitis and is more common in older children and young adults.

While a peritonsillar abscess may cause generalized throat pain, the pain is usually much worse on the side of the affected tonsil.

Other symptoms of a peritonsillar abscess include:

  • fever
  • fatigue
  • trouble talking
  • ear pain on the affected side
  • bad breath
  • drooling
  • soft, muffled voice

A peritonsillar abscess requires immediate medical attention.

Your doctor will likely use a needle or small incision to drain pus from the affected area. You might also be prescribed antibiotic therapy after the abscess is drained.

Canker sores are small sores that form in your mouth. They can form on the inside of your cheeks, on or under your tongue, inside your lips, or in the top of your mouth near the back of your throat. Most canker sores are small and round with a red border and a white or yellow center.

While small, they can be quite painful. When a canker sore forms in a back corner of your throat, you may feel pain on one side.

Most canker sores heal on their own within two weeks. In the meantime, you can find relief with home remedies or OTC topical medications, such as benzocaine (Orabase).

Your lymph nodes help your body fight off infections. When they swell, it usually means there’s a problem, such as a viral or bacterial infection. You may notice swollen lymph nodes in your neck, under your chin, in your armpits, or in your groin.

There are many lymph nodes in your head and neck regions. When they’re swollen, they may feel tender when you apply pressure to them.

Lymph nodes usually swell in the area near an infection. If you have strep throat, for example, the lymph nodes in your neck may swell. Sometimes only one lymph node will swell, causing a sore throat on one side.

In rare cases, swollen lymph nodes may be a sign of a more severe problem, such cancer or HIV. Talk to your doctor if you have any of the following symptoms with swollen lymph nodes:

  • nodes that are swollen for more than two weeks
  • weight loss
  • night sweats
  • long-lasting fever
  • fatigue
  • nodes that are hard, fixed to the skin, or growing rapidly
  • swollen nodes close to the collarbone or lower part of the neck
  • red or inflamed skin over swollen nodes
  • difficulty breathing

Glossopharyngeal neuralgia and trigeminal neuralgia, the latter sometimes called tic douloureux, are relatively rare nerve conditions that cause recurrent, sudden, excruciating pain around your ear canal, tongue, tonsils, jaw, or side of your face. Due to the location of nerves in your head and neck, the pain is usually on one side of the face only.

The pain of glossopharyngeal neuralgia is usually in the back of the throat or tongue. It’s often triggered by swallowing and usually lasts for a few seconds to a few minutes. You might feel an ache in the affected area after the acute pain episode.

The pain of trigeminal neuralgia is usually facial, but sometimes can occur in the mouth. Pain can be sudden and episodic or prolonged and progressive. Touching the face, eating, or even wind blowing on the face may set off an episode.

Both conditions are usually treated with medications used for neuropathic pain, such as carbamazepine (Tegretol), gabapentin (Neurontin), or pregabalin (Lyrica).

A tooth (periapical) abscess is a contained collection of pus caused by a bacterial infection. This pocket of pus grows at the tip of the root of your tooth. It can cause severe pain that radiates to your jawbone and your ear on one side of your face. The lymph nodes around your neck and throat may also be swollen and tender.

Other signs that your tooth is infected include:

  • sensitivity to hot and cold temperatures
  • pain while chewing
  • fever
  • swelling in your face or cheek
  • tender, swollen lymph nodes under your jaw or in your neck

Infection is common with impacted wisdom teeth, which are four molars in the back of your mouth that don’t have enough room to develop normally. Even when these teeth do emerge from the gums, they’re hard to clean, making them prone to infection. Infected wisdom teeth can cause jaw pain and swelling, making it difficult to open your mouth.

If your wisdom teeth are causing problems, your dentist will likely recommend removing them. If you have a tooth abscess, your dentist may make an incision to drain the pus. You might also need an antibiotic.

Laryngitis refers to inflammation in your voice box, also called your larynx. It’s usually caused by overusing your voice, irritation, or a viral infection.

You have two vocal cords in your larynx that normally open and close smoothly to make sound. When the cords become swollen or irritated, you might feel pain and notice that your voice sounds different. If one cord is more irritated than the other, you may feel throat pain on only one side.

Other symptoms of laryngitis include:

  • hoarseness
  • loss of voice
  • ticking sensation in your throat
  • rawness in your throat
  • dry cough
  • dry throat

Laryngitis often heals on its own within a few weeks, but it’s best to rest your voice during this period.

Most sore throats are caused by viral infections, such as the flu or the common cold. In rare cases, it can be a sign of something more serious. Seek immediate medical treatment if you have any of the following symptoms:

  • high fever
  • difficulty breathing
  • inability to swallow food or liquids
  • severe, unbearable pain
  • abnormal, high-pitched breathing sounds (stridor)
  • fast heart rate
  • signs of an allergic reaction

If you have throat pain on one side that doesn’t go away after a few days, work with your doctor to figure out what’s causing it. They may prescribe you antibiotic therapy or suggest OTC medications to relieve the pain or other symptoms.