What Can Cause a Sore Throat on One Side?

Medically Reviewed By Alana Biggers, M.D., MPH
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There are many reasons for a sore throat on one side, such as infection, inflammation, and throat injuries. Most cases of a sore throat improve quickly. However, a sore throat on one side may sometimes require medical care. Sore throat, also called acute pharyngitis, is a dry, painful, and scratchy sensation in the throat that may worsen when you swallow. It is often a symptom of illness, such as allergies or a mild infection.

This article discusses the causes of having a sore throat on one side, including the symptoms and treatment options. We will also suggest when to get help for your sore throat. 


A man standing at the sink and gargling water
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Tonsillitis can cause a sore throat on one side. It is inflammation that occurs when the tonsils are infected.

The tonsils are a pair of soft lymphatic tissue masses located at the back of your throat. They are part of your immune system and help clear infections. However, sometimes, doctors recommend their removal if they become enlarged and interfere with eating, sleeping, or breathing.

Viruses like influenza, herpes simplex, and measles are common causes of tonsillitis. But sometimes, bacteria can also be a cause. Tonsillitis is more common in children and teens, but adults can develop it, too. 

Treatment for tonsillitis depends on the cause. Doctors recommend antibiotics like penicillin to treat tonsillitis due to bacterial infections. Tonsillitis from viruses has no specific treatment.

Your doctor may suggest home remedies, such as staying hydrated, getting enough rest, and taking pain relief medications to help you feel more comfortable while your body clears the infection.

Learn more about tonsillitis.

Tooth infection

Bacteria often cause tooth infections. These can lead to a pus collection at the tooth root, also called a dental abscess. A tooth infection may cause the lymph nodes around the throat and neck to get inflamed. This can cause severe pain and sore throat symptoms on one side. 

Tooth infections often do not resolve on their own and require a dentist to treat them. In most cases, the dentist drains the pus and offers pain relief medications and antibiotics to treat the infection. Depending on the severity, they may recommend a root canal treatment or remove the tooth.

Learn more about tooth infections.

Swollen lymph nodes

There are many reasons why your lymph nodes may be swollen, such as:

Because the lymph nodes help the body clear infections by identifying and trapping germs, they sometimes get inflamed. This can lead to swelling and soreness. When this happens to the lymph glands in your neck, it can lead to a sore throat on one side. 

Swollen lymph nodes often resolve on their own without treatment. But in some cases, you may need to take antibiotics or antiviral medications to treat the cause.

Learn more about swollen lymph nodes.


Laryngitis is inflammation of the larynx, also called the voice box or vocal cords. This causes the larynx to become irritated and swollen, leading to voice changes. It can also cause a person to experience a sore throat on one side. Common causes of laryngitis include overuse of the vocal cords, irritation, and infection.

Learn more about laryngitis.

Postnasal drip

Postnasal drip is when excess mucus accumulates in the back of your throat. Sometimes, the mucus also drips from the nose down to the throat. Postnasal drip can lead to sore throat, persistent cough, and hoarseness. It can also cause painful ear infections.

Different causes of postnasal drip include:

  • allergies
  • spicy foods
  • colds and flu
  • chronic acid reflux
  • certain blood pressure medications

Treatment for postnasal drip depends on the cause and severity. Home remedies like saline nasal sprays and drinking plenty of water and warm liquids may help. 

Learn more about postnasal drip.

Throat injury or canker sores

Burns from hot liquid or food can injure the throat. Food allergies and highly acidic foods can also cause canker sores to form, leading to a sore throat on the affected side. Minor throat injuries may resolve with home remedies, while more severe injuries may require medical treatment.

While healing, avoid eating hot, spicy, and acidic foods. Gargling with warm salt water may also help.

Learn more about canker sores.

COVID-19 and sore throat

COVID-19 causes varying symptoms ranging from mild to severe, which may include a sore throat. A small 2022 study reviewed COVID-19 cases referred to the ear, nose, and throat emergency department between January 1 and January 23 of 2022. It indicated that the omicron variant of the virus affects the upper airways, leading to acute laryngitis.

A 2019 study that reviewed 127 cases of people admitted to the hospital for COVID-19 also highlighted that COVID-19 causes upper respiratory tract symptoms like sore throat and nasal congestion.

If you have a sore throat due to COVID-19, drinking warm liquids, like soups and tea mixed with honey, and gargling with salt water may help soothe throat irritation. Also, drink enough fluid to stay hydrated while you recover.

Additional causes of sore throat

Other causes of sore throats include:

  • Peritonsillar abscess: This infection causes pus to collect adjacent to or behind the tonsils.
  • Trigeminal neuralgia: This involves irritation of the trigeminal nerve, which helps your face experience sensations.
  • Gastroesophageal reflux disease (GERD): GERD is a condition that causes stomach contents, including acid, to flow back into the esophagus and throat repeatedly.
  • Noncancerous or cancerous tumors: Tumors that develop around the throat area can cause sore throat.

When to get medical help 

Symptoms like pain when swallowing, hoarse voice, and fever often accompany a sore throat. However, they are often not severe and resolve with time. Most cases of sore throats, particularly those from viral infections, do not require treatment. 

In rare cases, a sore throat can signify a more serious condition. Get medical help if you also experience the following:


If you have a sore throat on one side, it could be a symptom of a minor infection. It could also be a symptom of an injury or a condition that needs medical attention.

If a sore throat persists or worsens, get medical help and work with your healthcare team to figure out the cause and treat it. Most cases of sore throat resolve when treated with antibiotics, over-the-counter medications, and home remedies.

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Medical Reviewer: Alana Biggers, M.D., MPH
Last Review Date: 2022 Oct 24
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THIS TOOL DOES NOT PROVIDE MEDICAL ADVICE. It is intended for informational purposes only. It is not a substitute for professional medical advice, diagnosis or treatment. Never ignore professional medical advice in seeking treatment because of something you have read on the site. If you think you may have a medical emergency, immediately call your doctor or dial 911.
  1. El-Anwar, M. W., et al. (2021). Analysis of ear, nose and throat manifestations in COVID-19 patients. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8321632/
  2. Erazo, D., et al. (2022). Dental infections. https://www.ncbi.nlm.nih.gov/books/NBK542165/
  3. Piersiala, K., et al. (2022). Acute odynophagia: A new symptom of COVID-19 during the SARS-CoV-2 Omicron variant wave in Sweden. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC9115132/
  4. Tonsillitis. (2017). https://medlineplus.gov/tonsillitis.html