A sore on the side of the tongue can develop for various reasons, including canker sores, cold sores, or a minor injury. Less commonly, a sore on the tongue may be a sign of cancer.

In some cases, severe, recurring, or persistent mouth sores can be a symptom of an underlying condition.

This article discusses possible symptoms of sores on the side of the tongue. It also looks at the common causes, treatments, and remedies for tongue sores, as well as when to speak to a doctor.

a person is looking at their tongue in a magnified mirrorShare on Pinterest
RunPhoto/Getty Images

Sores on the side of the tongue can look and feel different depending on what is causing them. They may be:

  • small and red
  • larger, with a white or gray center and red edges
  • open and bleeding

Sores on the side of the tongue can also occur alongside other symptoms, such as swelling or difficulty chewing or swallowing.

Minor conditions are responsible for most mouth sores, but sores on the side of the tongue can be a sign of an underlying condition that may require medical attention.

Canker sores, or mouth ulcers, are small painful sores that can appear on the tongue. The symptoms of canker sores include:

  • small sores that begin as a red bump and then develop a white or gray center with flat red edges
  • pain and soreness
  • symptoms that worsen when a person eats salty, spicy, or acidic foods

Canker sores tend to heal on their own within a few days. They are not contagious.

Doctors do not know exactly what causes canker sores, but the United Kingdom’s National Health Service (NHS) note that the following factors can trigger them:

Hormonal changes, such as those that take place during pregnancy, and genetics can also make canker sores more likely for some people. Those with chronic conditions, such as inflammatory bowel disease (IBD) and celiac disease, may also experience them.


There is no permanent cure for canker sores. Often, they heal on their own without medical treatment. However, there are ways to relieve the symptoms.

People can obtain over-the-counter (OTC) pain medication, such as acetaminophen (Tylenol), from a pharmacist. There are also topical products for canker sores that people apply inside the mouth to numb the pain.

Frequent canker sores may indicate an underlying condition, such as a vitamin deficiency, which may require medical attention.

Cold sores are fluid-filled blisters that occur due to an infection with the herpes simplex virus (HSV). They typically appear around the mouth but sometimes develop on the tongue.

The symptoms of cold sores include:

  • a tingling or burning sensation before the cold sore develops
  • painful, fluid-filled blisters that rupture, leak fluid, and then scab over
  • sores that heal and then reappear, sometimes in response to stress or an illness

Some people also experience fever during cold sore flare-ups.

Cold sores may take a couple of weeks to heal fully. During that time, they are contagious because the fluid inside them contains HSV. For this reason, it is important to avoid picking the sores and take steps to prevent HSV from transmitting others.


There is no cure for cold sores, but for most people, neither the sores nor the virus causes serious problems. During cold sore flare-ups, people can use OTC pain medications to ease pain and swelling.

People with severe cold sores or a compromised immune system can obtain antiviral medication from a doctor. These medications shorten the duration of cold sores, but they do not entirely prevent them.

A person should speak with a healthcare professional if their cold sores do not go away after a few weeks.

Lichen planus is a chronic autoimmune condition that can affect the skin and the inside of the mouth. Oral lichen planus often only occurs inside the mouth, most often on the inside of the cheeks and the sides of the tongue.

The symptoms of lichen planus include:

  • painful ulcers
  • white or lace-like patches that itch
  • inflamed and peeling gums
  • raised red or purple areas on the body, which doctors call plaques
  • yellowish-brown plaques on the palms and soles

Several factors can contribute to lichen planus, including genetics, an injury inside the mouth, and viral infections such as hepatitis C. The condition can clear within a few years, but for oral lichen planus, it often takes longer.


Doctors can prescribe steroid medications to relieve the symptoms of lichen planus. Alternatively, they may recommend other medications and ointments.

Severe cases may require a combination of medications and different therapies, such as UV light therapy.

Erythroplakia is a condition that causes red patches inside the mouth. It can occur anywhere in the mouth, including on the side of the tongue. If the patch is relatively small, a person could mistake it for a sore or an ulcer.

People may not notice erythroplakia, as it can be flat and painless and cause no other symptoms. However, this type of lesion is sometimes precancerous.

According to the American Cancer Society, the most common causes of erythroplakia are:

  • chewing tobacco
  • smoking
  • wearing dentures that rub

Erythroplakia may also occur alongside leukoplakia, a similar condition that causes white lesions.


Treating this condition typically involves identifying the cause of the lesion and removing it. For example, a person may need to stop smoking or have their dentures refitted.

However, it is important that a person speaks with a doctor about the possibility of erythroplakia so that the doctor can perform a biopsy to test for cancer.

Cancer can lead to mouth sores in several ways. People with oral cancer may experience lesions or growths on the tongue that resemble sores. They may appear as white or red patches that do not go away after two weeks. The growth will often be painless and small to begin with, but it may spread quickly.

People with other types of cancer may also develop mouth ulcers in response to some kinds of chemotherapy, immunotherapy, or radiation therapy.


Of all oral cancers, the majority are squamous cell carcinomas. Doctors may remove these via surgery.

More advanced oral cancer may require a combination of surgery, radiation therapy, and medication.

How people manage the symptoms of mouth sores can depend on the cause. However, the following tips may help people with minor, temporary sores.

To reduce the pain of tongue sores, people can try:

  • avoiding acidic, spicy, or salty foods
  • avoiding hard or crunchy foods
  • avoiding eating too fast or chewing gum, as this may cause a person to bite the sore accidentally
  • eating chilled foods, as the cool temperature can relieve pain
  • using a softer toothbrush
  • using a straw for drinks
  • using a mouth rinse, such as a saline rinse or medicated mouthwash

To prevent recurring canker sores from coming back, people can try:

  • making sure food and drinks are not too hot before eating
  • eating slowly, taking time to chew each mouthful
  • eating a balanced, healthful diet
  • addressing any vitamin or mineral deficiencies
  • managing food intolerances or allergies
  • switching to gentle, nonirritating mouthwash and toothpaste
  • speaking to a dentist about any braces, mouth guards, or dentures that rub

It is not always possible to prevent cold sores, but some people find that tiredness or stress can trigger flare-ups. If this is the case, it may help to stick to a regular sleep schedule where possible or to practice stress-relieving activities, such as mindfulness or yoga.

According to the NHS, tobacco use and drinking alcohol of oral cancer. Stopping smoking and drinking lowers the risk of oral cancer.

People should speak with a doctor or dentist if they experience:

  • sores that do not heal after 1–2 weeks
  • recurring sores on the side of the tongue
  • a sore or red patch that bleeds easily or frequently
  • painless sores or lesions that do not go away
  • itchy white patches or lines inside the mouth
  • unexplained lumps, bumps, or growths
  • sores alongside painful or swollen gums
  • sores that accompany other symptoms, such as a bad odor, fever, or a rash elsewhere in the mouth or on the body
  • pain or difficulty chewing or swallowing

Many tongue sores are canker sores or cold sores. These can cause pain and discomfort but will typically heal on their own. People can take OTC medications or try topical remedies for symptom relief.

Recurring sores on the side of the tongue may indicate an underlying condition. In these cases, a doctor or dentist can help determine the cause and put a treatment plan in place.