Mar. 18, 2025

Sore Throat On One Side Only: Causes & When It’s Serious

Kaitlyn Alemida, PA

Physician Assistant

Sore Throat On One Side Only: Causes & When It’s Serious

A woman staring out with while scratching the back of her head

A sore throat is a common symptom that most people experience at some point in their life for a number of different reasons. However, it may be a little confusing when the pain is only on one side of the throat. While it’s not usually serious, it’s important to know when it could be a sign of something that requires urgent medical attention.

This article will explore the various reasons for having a sore throat on one side, explain how symptoms may point to certain underlying causes, and let you know when to seek further medical care.

How a sore throat can be localized to one side

When you have a bacterial or viral infection, it tends to cause what’s called a “diffuse” sore throat, felt on both sides. A sore throat that is isolated to just one side typically occurs because something is affecting the physical structures of one side of the throat, head, or neck.

The throat itself includes parts of different systems like the tonsils, muscles, and lymph nodes, which can all be impacted differently depending on the cause. When one side of the throat is painful, it could be due to an infection, injury, or inflammation in a particular area.

Causes of a sore throat on one side only

It may surprise you to learn that several things can cause a sore throat on only one side. We will explore some of the most common causes below.

Peritonsillar abscess

A peritonsillar abscess is a collection of pus that forms near the tonsils, usually due to a bacterial infection like tonsillitis or strep throat. This abscess can cause severe pain, typically only on the side of the throat where it’s located. If left untreated, it may cause difficulty breathing or swallowing and can lead to more serious complications like sepsis.

Other symptoms may include:

Severe throat pain on one side
Fever
Swelling of the tonsil or neck
Difficulty opening the mouth
Bad breath
Ear pain on the same side

A peritonsillar abscess requires urgent medical attention. If you experience the above symptoms, you should seek immediate medical attention.

Tonsil stones

Tonsil stones, also known as tonsilloliths, are small, hard deposits that form in the crevices of the tonsils. They are made up of bacteria, dead cells, and other debris, such as food, that become trapped in the tonsils. While tonsil stones are often harmless, they can cause discomfort, including a sore throat on one side, especially if the stone becomes large or infected.

Other symptoms may include:

A feeling of something stuck in the back of the throat
Bad breath
Sore throat
White or yellowish spots on the tonsils

If the tonsil stones are causing persistent pain, difficulty swallowing, or if they become infected, this should prompt a visit to the doctor for removal and antibiotics if needed. However, most of the time, tonsil stones require no treatment and will fall out on their own.

Dental infection

Dental problems like an abscessed tooth, gum infection, or cracked tooth can cause pain that radiates to the throat. A dental abscess occurs when a bacterial infection forms in the tooth or gum, causing swelling, a collection of pus, and pain that can extend to the throat. Usually, these symptoms are experienced only on the side of the affected tooth.

Other symptoms may include:

Severe toothache
Swelling or redness in the gums
Bad taste in the mouth
Fever
Sensitivity to hot or cold temperatures
Pain while chewing or biting

If you experience a sore throat on only one side alongside a severe toothache, it is important to visit a dentist. Dental abscesses may require drainage and antibiotics to treat the infection.

Salivary gland infection

Sialadenitis is an infection of the salivary glands—small organs responsible for producing saliva. This condition typically affects one of the major salivary glands located along the jaw and side of the neck. This can cause pain in the throat, particularly on one side, if the infected gland becomes enlarged. A blocked duct in the salivary gland, dehydration, or a bacterial infection can all trigger sialadenitis.

Other symptoms may include:

Pain and swelling on one side of the face or neck (near the jaw or under the ear)
Dry mouth or difficulty swallowing
Bad-tasting or unusually thick saliva
Fever and chills
Increased swelling and pain when you salivate

If you have swelling in the mouth or neck area along with pain, fever, or difficulty swallowing, you should see a doctor right away. Sialadenitis caused by a bacterial infection may require antibiotics, and in some cases, the blockage in the gland needs to be cleared. If left untreated, salivary gland infections can lead to complications such as abscesses.

Other causes of a sore throat on one side based on another symptom or condition

Telling your doctor you have a sore throat on only one side already helps them narrow down the potential causes. Looking at additional factors can break things down even further.

Sore throat on left side only

A sore throat on the left side only can be from any of the conditions listed above, including tonsil stones, a peritonsillar abscess, a dental infection, or a salivary gland infection.

Sore throat on right side only

Just as with the left side, a sore throat on the right side only can point to some previously mentioned causes, such as tonsil stones, a peritonsillar abscess, a dental infection, or a salivary gland infection.

Sore throat on one side when swallowing

If you are experiencing pain while swallowing, the cause is likely within the throat itself. Peritonsillar abscesses and tonsil stones that lead to one-sided swelling may cause pain with swallowing. Causes outside of the throat, such as a salivary gland infection or dental infection, are less likely to cause pain with swallowing, but it’s still possible.

Sore throat on one side with ear pain

Pain in both the throat and the ear can occur when the infection or inflammation in the throat irritates the ear canal. Similarly, an ear infection on one side can cause swelling of lymph nodes in the neck, leading to pain that may affect the throat.

Sore throat on one side with a toothache

As mentioned before, a tooth abscess or dental infection can cause swelling and pain that radiates to the throat. If you experience both a sore throat and a toothache on one side, it is important to see a dentist or healthcare provider before the infection worsens.

When you should see a doctor for a sore throat on one side

Some conditions, like tonsil stones, are benign. While they may be annoying, they don’t require medical attention unless they really bother you. Many other causes of one-sided throat pain do, however, require medical attention.

You should see a doctor if:

You have a sore throat for more than a week.
You have tooth pain.
You are experiencing symptoms indicating an infection, such as a fever.

You should go to the emergency room if:

You are having difficulty breathing or swallowing due to the swelling.
You are unable to fully open or close your mouth or experience drooling.
You are unable to move or turn your neck from side to side.

Questions to ask your doctor about a sore throat on one side

What could be causing my symptoms?
Is it normal to experience a sore throat on only one side?
Will this condition eventually spread to the other side of my throat?
What treatment options are available for my symptoms?

Frequently asked questions: sore throat on one side

People usually experience a sore throat that covers both sides. If you are experiencing one-sided throat pain, you may have some additional questions. Here are some of the most frequently asked questions about this symptom and what you need to know.

What if you feel a painful lump in your throat, but only on one side?

If you feel a painful lump in your throat on only one side, this is likely a result of tonsil swelling. This may be due to an abscess or tonsil stone. Significantly swollen lymph nodes or salivary glands on one side of the neck may also lead to the feeling of a painful lump in your throat. Although unlikely, a foreign object should also be considered.

What if your throat has been sore on one side for a month?

If you experience a sore throat on one side for more than a month, you should consult with your healthcare provider to rule out tonsil stones or more serious issues. Some chronic conditions can cause swelling of the lymph nodes, abnormal growths, or infections.

What should you do if your throat is sore on one side only during a pregnancy?

If you are pregnant and experiencing a sore throat on one side, you should consult with your healthcare provider to rule out infections that could pose risks during pregnancy.

Final thoughts: sore throat only on one side

Experiencing a sore throat on only one side can be concerning, but it is not always a sign of something serious. Causes related to the tonsils, the teeth, the ears, and even the salivary glands can all be to blame for one-sided throat pain. If the pain persists for more than a few days or is accompanied by other symptoms like fever, difficulty swallowing, tooth pain, or trouble opening or closing the mouth, it is important to speak with your healthcare provider.

General Medicine follows a strict editorial process, including using real experts to write our articles, vetted primary sources, fact-checking, a secondary medical review, and updates as necessary. This article was medically reviewed and fact checked by Dr. Jennifer Nadel, MD.