Patient education: Mouth sores (The Basics)

What causes mouth sores? — 

Mouth sores can happen with different conditions, including:

●Canker sores – These are open sores (also called "ulcers") that are white or yellow in the middle, and red around the edges (picture 1). Certain things make canker sores more likely to develop. These include certain foods, infections, and biting the tongue or inside of the cheek. Braces and poorly fitting dentures can also cause canker sores.

●Mouth cancer (also called "oral cancer") – Mouth cancer can cause sores or growths inside the mouth or on the lips or tongue (picture 2). Mouth cancer can also cause the inside of the mouth, lips, or tongue to turn white or dark. Usually, these symptoms are not painful at first. Some people find out they have mouth cancer only after a routine medical or dental exam.

●Leukoplakia – This condition causes white or gray patches inside of the mouth or on the tongue (picture 3). They can be thick and usually develop over time. Smoking or chewing tobacco and drinking alcohol can cause it. It can sometimes turn into mouth cancer after a few years, but this is uncommon.

●Cheilitis – This is a condition that makes the lips look "chapped" and get red and scaly (picture 4). A few things can cause it, including windburn, licking the lips a lot, and certain medicines and foods. There is more than 1 type of cheilitis. "Actinic" cheilitis is caused by too much sun and can later turn into lip cancer. "Angular" cheilitis is caused by an infection, and usually happens in older people whose dentures don't fit well. It causes redness and cracking in the corners of the mouth.

●Dark spots – In people with dark-colored skin, dark spots are usually normal. But in people with light-colored skin, dark spots can be a sign of a serious problem.

Should I see the doctor, dentist, or nurse? — 

Yes. See your doctor, dentist, or nurse if:

●Your mouth sores spread, or you have a growth in your mouth or on your tongue or lips.

●You have a patch of dry, scaly skin on your lips that doesn't heal.

●You have a white patch in your mouth or on your tongue.

●You have a dark spot in your mouth and have light-colored skin.

●Your dentures don't fit well.

●Your mouth sores change colors.

●Your pain gets worse, or you have trouble eating, swallowing, or talking.

●Your symptoms last longer than 2 weeks, or heal but then come back.

Will I need tests? — 

Maybe. The doctor or nurse will talk with you and do an exam. They might also do a test called a biopsy. The doctor will take a tiny sample of the sore, growth, or area of color change. Then, another doctor will look at the sample under a microscope.

How are mouth sores treated? — 

Treatment depends on the cause of your symptoms and whether they bother you.

●Canker sores usually get better on their own within a few weeks. To help with pain, you can use an over-the-counter medicine made to soothe canker sores. If your symptoms are severe, your doctor might prescribe a mouthwash or medicine to use on the area.

●Mouth cancer is usually treated with 1 or more of these:

•Surgery

•Radiation therapy – This kills cancer cells.

•Chemotherapy – These are medicines that kill cancer cells or stop them from growing.

●Leukoplakia is sometimes treated with surgery to remove the abnormal patches.

●Treatment for cheilitis depends on the type of cheilitis. Your doctor might recommend you use petroleum jelly on the area. If you have an infection, they will prescribe a medicated ointment for you to use on the area. If poorly fitting dentures caused your infection, ask your dentist to fix them.

What can I do on my own? — 

If you have canker sores:

●Follow your doctor's instructions on how to care for your mouth.

●It might help to rinse your mouth with ice water or suck on ice chips. You can also gargle with warm salt water a few times each day. To make salt water, mix 1/2 teaspoon (2.5 grams) of salt with a cup (240 mL) of warm water.

●Take all your medicines as instructed.

●Brush and floss your teeth regularly. Use a toothbrush with soft bristles.

●Avoid eating or drinking hot and spicy foods or salty foods like chips if they bother you.

More on this topic

Patient education: Mouth sores from cancer treatment (The Basics)
Patient education: Cold sores (oral herpes) (The Basics)
Patient education: Tongue cancer (The Basics)
Patient education: Leukoplakia (The Basics)