A sore throat is a common symptom of many conditions. However, some causes, such as swollen lymph nodes and direct injury, may only affect one side of the throat.

There are many possible reasons for one side of the throat feeling sore, and it may not always be clear what the root cause is.

In this article, we look at possible causes of a sore throat on one side. We also discuss when to see a doctor.

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The body’s lymph nodes act as filters, helping to identify and trap germs, such as viruses and bacteria before they can infect other areas. As they do this, the lymph nodes may swell up and become sore.

The lymph nodes closest to the throat are on either side of the neck. Sometimes only one node in the area is sore, which can cause a sore throat on one side.

Some conditions that may lead to swollen lymph nodes include:

Learn more about swollen lymph nodes here.

During nasal congestion, mucus and fluid drain down the back of the throat. This is known as postnasal drip. Continual drainage can irritate the throat, leading to a feeling of soreness or scratchiness.

This drainage may cause irritation and soreness in a specific part of throat and may feel like one side is raw and inflamed.

Tonsillitis describes inflammation of one or more tonsil. The tonsils are at the back of the throat, and a virus or bacterium usually causes the infection and inflammation.

An infection in just one tonsil can cause pain on one side. It may also cause a fever, trouble swallowing, and noisy breathing.

An abscess is a contained, pus-filled lump within the tissue. A bacterial infection usually causes it.

A peritonsillar abscess forms in the tissues near the tonsils. It may cause intense pain on one side of the throat. It may also cause fever, swollen lymph nodes, and trouble swallowing.

A person with a peritonsillar abscess requires urgent medical care. In severe cases, it can interfere with breathing.

Many things can injure the back of the mouth or throat, including:

  • burns from hot food or liquid
  • food with sharp edges, such as chips or crackers
  • endotracheal intubation, which is the insertion of a tube down the throat to help with breathing

If one side of the throat is sore from scraping or burning, gargling with warm salt water may help to soothe symptoms.

Gastroesophageal reflux disease (GERD) is a condition that causes the stomach’s contents, including stomach acid, to back up into the food pipe and throat.

GERD may be worse at night and when lying down. If stomach acid backs up when a person is lying on their side, it may lead to soreness on one side of the throat.

If GERD goes untreated for too long, it can damage the food pipe and throat.

Learn more about acid reflux at night here.

As the name implies, this viral illness usually causes sores to form on the hands, feet, and mouth. Sores can develop in the back of the mouth, near the sides of the throat, and one side may be more affected than the other.

Hand, foot, and mouth disease usually occurs in children under 5 years of age, but it can also spread to older children and adults.

Learn more about hand, foot, and mouth disease here.

In adults, other types of sores, such as aphthous ulcers, are more common and can often cause one-sided symptoms.

Overusing or misusing the voice can lead to lesions or nodules on the vocal cords. A lesion may form on one side, causing one area of the throat to be sore. However, not all people who damage the vocal folds will experience pain.

A person with a vocal cord lesion will usually notice a change in their voice, such as hoarseness.

These types of lesions are usually treatable. Resting the voice and vocal therapy are typically used to correct vocal cord lesions. In some cases, lesions will require surgery.

While they are among the least common causes of a sore throat, cancer can affect the throat and surrounding areas. They may be benign or cancerous.

A tumor can cause soreness on one side of the throat. It may occur on the tonsils, in the back of the throat or tongue or in the larynx, which is commonly known as the voice box.

Usually, a tumor will also lead to symptoms that do not occur with common infections and illnesses, such as blood in the saliva and unexplained weight loss.

Learn more aout throat cancer here.

If a throat is sore on one side, the cause is usually a minor viral infection, such as the common cold. However, it is important to see a doctor if the following symptoms also appear:

  • an inability to eat or drink because of the sore throat
  • a severe sore throat that lasts for more than 7 days
  • swollen lymph nodes that get bigger as the sore throat feels better
  • difficulty breathing, or a feeling of the throat closing
  • trouble swallowing
  • a fever
  • pus in the back of the throat
  • body aches or joint pain
  • an earache
  • a rash
  • blood in the mouth
  • coughing up blood
  • a lump in the neck
  • a sore throat that goes away and comes back

Below are frequently asked questions relating to soreness in one side of the throat.

Why is one tonsillar lymph node swollen?

Swelling on one side of the throat can occur due to localized damage or injury, tumors, infection, and more. People can speak with a doctor if swelling does not go away or if other symptoms start to appear.

Can a person have a swollen tonsillar lymph node but not be sick?

Swelling on one side of the throat may occur due to localized damage rather than an illness. People can speak with a healthcare professional for a proper diagnosis.

Why does my tonsillar lymph node hurt?

There are several causes of soreness on one side of the throat, including:

  • localized damage or lesions
  • infections
  • tumors
  • acid reflux

How does a person treat swollen tonsillar lymph nodes?

Treatment for swelling on one side of the throat will depend on its cause. In cases of injury, painkillers and rest are often suitable, whereas bacterial infections may require antibiotics. However, other more severe causes may require medical interventions.

There are many reasons why a person may feel soreness in only one side of their throat. Direct injury to a specific area, localized infections, and swollen lymph nodes may all cause irritation and discomfort on one side of the throat but not the other.

Treatment for a sore throat will depend on the cause. It is important to seek medical assistance if throat pain becomes unbearable or persists for several days.

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