Cancer Mouth Sores | Causes and Treatment Explained

Cancer mouth sores are also called oral mucositis or mucosal erosions. They are open areas of the mouth that are not caused by dental disease or injury. They can be painful, but they usually heal on their own within a few days to weeks. However, severe cases that are left untreated may go on for months.

The most common cause of cancer mouth sores is chemotherapy (chemo). Chemo is a drug used to kill cancer cells. Unfortunately, chemo kills both healthy and unhealthy cells, so it also damages the lining of your mouth. Other causes include radiation, targeted, hormonal, biological, and stem cell transplantation.

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For relief, you can use Dr. Brite products that are designed to help relieve pain and soreness. They also help prevent infection and promote healing of oral mucosal tissue affected by chemotherapy treatments. Keep reading to learn more about Cancer mouth sores:

Does Cancer Cause Mouth Sores?

Cancer can cause painful mouth sores, but they're not familiar. You may get them when you have cancer because the treatment for your cancer kills healthy cells and cancerous ones.

Cancer-related mouth sores' major cause is radiation therapy or chemo. Radiation therapies utilize high doses of X-rays that kill cancer cells in their tracks.

Chemotherapy drugs target cancer cells with high doses of poisons that stop them from growing and dividing into new cells. Unfortunately, the treatment may also cause damage to healthy tissue nearby, which can lead to painful mouth sores.

a person bringing drugs and water to the cancer patient

What Do the Early Stages of Mouth Cancer Look Like?

Cancer of the mouth is a severe condition, and if left untreated, it can lead to death. The early stages of mouth cancer can be challenging to detect. You may have some of the following symptoms:

  • White or red patches on either lips, gums, or tongue. You could also describe it as a "dirty" looking area which is not normal for you

  • Red or white patches inside your mouth (on your tongue, tonsils, or throat)

  • Sores that bleed easily do not heal and do not go away with antibiotics

  • A lump on the side of the neck (near your jaw bone)

  • Pain when chewing or swallowing food

  • Difficulty moving your tongue around

What Kind of Cancer Causes Mouth Sores?

woman holding a mirror

Some cancers can also cause mouth sores. These include:

Cancer of the Salivary Glands

These are small glands located throughout the body that produce saliva. Saliva helps keep your mouth moist, aids in chewing and swallowing food, fight off bacteria and provides nutrients for your teeth. Salivary gland cancers are rare but can occur anywhere in the body with a salivary gland.

Squamous Cell Carcinoma

It's a type of oral cavity that is a prevalent type of cancer that affects the lips, mouth, and throat. It usually appears as a sore that does not heal within two weeks or as a bump or lump on the surface of mucous membranes.


Lymphoma is cancer that starts in your body's lymphocytes (white blood cells). If you have non-Hodgkin lymphoma, you may have sores around your lips, cheeks, or gums that do not heal within two weeks. These sores usually appear as lesions on your tongue or inside your cheeks.

Throat Cancer

Throat cancer can affect any part of your throat but most often affects the tonsils and base of the tongue. If you have this kind of cancer, you may have sores in your mouth that do not heal within two weeks or develop white patches.

a doctor with a patient

Types Of Mouth Sores:

The most common mouth sores are:

  • Canker sores. These are whitish or yellowish ulcers that may be painful and last for several weeks. The primary cause is irritation and inflammation of the mouth lining (mucosa).

  • Non-cancerous (benign) growths in the mouth are commonly called cankers and cold sores. A virus usually causes them, and they're contagious.

  • Cold sores (also called fever blisters). These are clusters of blisters that may be painful and last for ten days. A virus causes cold sores. They often appear on the lips, but they can also appear inside the mouth or on the face or nose.

  • Mouth ulcers (also called aphthous ulcers). These are small, round sores that develop in groups and may be painful when they first appear but disappear within a few days or weeks without treatment. Mouth ulcers can occur at any age but tend to be more common in young children and older adults than in other age groups.

  • Aphthous ulcers (canker sores) appear as small, round, painful ulcers on the inside of your mouth or your lips, tongue, and gums. They're usually red but can also be yellowish or white. The pain usually lasts for about one week before healing on its own. You can have several outbreaks a year.

a man showing his lips

What Can One Do to Prevent Mouth Sores?

There are several things you can do to prevent mouth sores:

  1. First, get a dental checkup before starting treatment. If you have an infection in your mouth, it will affect the success of your treatment and increase your risk of developing mouth sores. Your dentist or oral health care professional will be able to identify any problems before they become serious.

  2. Observe good care of your overall oral health during treatment. Brush and floss regularly, drink plenty of water and eat a healthy diet to keep your gums moist and firm.

  3. Stop smoking if you smoke cigarettes regularly (or chewing tobacco). Smoking makes it harder for your body to fight off infections, so quitting is one way to reduce your risk of developing mouth sores during cancer treatment.

  4. Stop eating or drinking acidic foods and drinks such as citrus fruits or juices (including lemonade) because these foods can irritate the lining of the mouth and cause sores to develop more quickly.

drinks with fruits and straws

Mouth Sores Caused by Cancer Treatment: How to Cope

Here are some tips on coping with mouth sores:

Eat Soft Foods

It's easier on your mouth if you avoid hard or chewy foods such as meat, nuts, and crunchy chips. Instead, try eating yogurt or cottage cheese instead of ice cream or frozen yogurt.

Use a Straw if Necessary

Drinking through a straw helps prevent biting your lip or tongue while drinking, aggravating mouth sores.

Avoid Hot Foods and Beverages

Hot foods and liquids may burn your sore lips, tongue, and sore gums and make them even more painful than they already are. Instead, drink warm beverages such as tea or chicken broth if you need something soothing for your throat during chemotherapy sessions; avoid alcohol because it dries out the sores causing more pain.

soft food on the table

Home Remedies for Mouth Sores

The below home remedies will help relieve the pain from mouth sores:

  • Rinsing with salty water may soothe pain and promote healing. Use a soft-bristled toothbrush to brush around the sore area gently.

  • Using ice chips or an ice pack may help relieve pain associated with oral mucositis (mouth ulcers).

  • Avoid spicy foods or candies that irritate your mouth. Avoiding acidic foods such as lemons, oranges, and tomatoes will also help reduce irritation.

  • Drinking plenty of fluids helps keep tissues moist and lessens irritation from dry mouth. Sucking on lozenges may provide temporary relief from soreness and dryness.

soft toothbrushes

Treatment for Mouth Sores

There are many treatments available for mouth sores including:

Cold Therapy (Cryotherapy)

You'll need to apply ice packs to the affected area for 10 minutes every two hours. It numbs the site so it doesn't hurt as much, but it might not speed up the oral healing process.


If a bacterial infection is causing your mouth sores, your healthcare provider may prescribe antibiotics. These drugs kill bacteria in the body and can help treat mouth sores caused by infections.

Pain Relievers (Analgesics)

These drugs numb pain and reduce inflammation in your body. They include aspirin, ibuprofen (Advil), acetaminophen (Tylenol), and naproxen sodium(Aleve). Your healthcare provider should educate you on how much of these medicines to take and when to take them.

Mouth rinses with lidocaine or benzocaine. These rinses numb the inside of your mouth and suppress pain when eating or drinking. Lidocaine can also help relieve mouth pain caused by radiation therapy for head and neck cancer patients.

a man taking a medicine

What Happens If Mouth Sores Are Left Untreated and Become Severe?

If you don't treat mouth sores, they can lead to:


Severe mouth sores allow germs to enter the bloodstream, leading to sepsis (a severe blood infection). Sepsis is fatal if not treated promptly with antibiotics or intravenous fluids.

Difficulty Eating or Swallowing

Severe mouth sores make it painful to eat and drink so you may need a feeding tube inserted through your nose into your stomach (nasogastric tube). A nasogastric tube also lets you receive nutrition while avoiding foods that aggravate your sore throat and mouth sores.

Get Relief Today!

Cancer mouth sores can be a challenging condition to treat. They typically appear in the mouth as ulcers, sores, or red and painful lesions to the touch. These sores can be caused by various factors, including radiation therapy and chemotherapy.

The good news is that Dr. Brite'sproducts can help with this condition. The complete line of oral care products contains natural ingredients, including aloe vera gel, and vitamin E, shown in studies to relieve pain and promote healing of oral ulcers associated with cancer treatments.

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