White Spots in the Mouth: What Causes Them?

Table of Contents
View All
Table of Contents

White spots in the mouth can be caused by a variety of conditions including fungal or viral infections, canker sores, and a condition known as leukoplakia. Leukoplakia is a condition that is commonly caused by heavy tobacco or alcohol use. The term "leukoplakia" literally means "white patch" (leuko means white and plakia means patch).

The white spots in the mouth caused by leukoplakia could become cancerous. In fact, according to the Cleveland Clinic, once leukoplakia develops, within approximately 15 years, nearly 3% to 17.5% of people will go on to be diagnosed with a common type of skin cancer called squamous cell carcinoma.

Other underlying causes of white spots in the mouth may or may not be linked with mouth cancer.

A bathroom scene with vitamin A, pills, a tooth brush, and a tube with paste or cream (How to Prevent White Spots in the Mouth)

Verywell / Laura Porter

Causes of White Patches in the Mouth

There are many reasons that white patches can develop in the mouth, including different forms of leukoplakia, fungal infections, and various types of viruses.


Leukoplakia causes white spots that appear in the mouth due to heavy smoking, chewing tobacco, or alcohol use. Two main types of leukoplakia are:

  • Homogenous: An even-colored, thin patch that is consistent in appearance and primarily white; it may be wrinkled or smooth or may have a ridged surface.
  • Non-homogenous: Patches that are primarily white, red, and irregularly shaped. The patches may be flat or they may appear nodular or elevated. Non-homogenous patches may appear nodular (speckled) and ulcerated (an open sore), and these qualities may indicate that the leukoplakia is more likely to become cancerous than the homogenous type. 


A condition referred to as “oral hairy leukoplakia” involves white patches on the tongue or other areas of the mouth.

Oral hairy leukoplakia is associated with the Epstein-Barr virus as well as other causes of a weakened immune system, such as human immunodeficiency virus (HIV).

The patches may appear hairy, thus the name. This type of leukoplakia is present throughout a person’s lifetime.

Oral Lichen Planus

Oral lichen planus is a chronic (long-term) inflammation that involves the mucous membranes inside the mouth.

This type of oral spot may appear white, red, lacy, or it may exhibit itself as red inflamed tissue or lesions (open sores). Symptoms may include:

  • A burning sensation
  • Pain
  • Discomfort at the site of the lesions

Oral Thrush

Oral thrush is caused by an overgrowth of fungus in the mouth. It is considered a type of fungal infection and is treated with oral antifungal medication.

Thrush is caused by an organism called Candida albicans, which can also cause vaginal infections, as well as diaper rash. The symptoms of oral thrush include white patches that may appear as a white coating of the mouth. Thrush can also cause redness and burning of the mouth.

Canker Sores

Canker sores usually appear as a single, large white patch that may be reddened around the white area of the patch.

There are several underlying causes of canker sores, including irritation from certain types of food or drink, tobacco use, injuries from accidentally biting the cheek or lip, and other causes. Canker sores are usually painful, but in most instances, they heal on their own. 

Mouth Cancer

There are several factors linked with whether leukoplakia ends up causing cancer. Examples include:

  • The type of leukoplakia
  • The size and shape of the leukoplakia
  • The presence of abnormal cells in the leukoplakia
  • The location of the white patches (there is conflicting evidence as to whether having white patches on the floor of the mouth or the underside of the tongue could pose a higher risk of cancer)
  • The presence of white or red masses (that appear pebble-like)
  • The presence of ulcerations, bleeding, or nodules


Symptoms of leukoplakia include:

  • One or more white patches (that cannot be wiped off) on or under the tongue, or inside the cheeks
  • No pain or other symptoms present

Symptoms that are linked with other causes of white spots in the mouth include:

  • Redness around the white spot
  • Pain
  • Burning sensation
  • Discomfort


Often the first time that leukoplakia is noticed is when a person goes to the dentist or has a routine physical examination. This is because there are no signs or symptoms of leukoplakia, other than the appearance of white spots in the mouth.

A diagnosis of leukoplakia involves ruling out other causes of white patches in the mouth, such as:

  • Rubbing/friction inside the mouth caused by dentures (or other causes)
  • Repeatedly biting the inside of the cheek
  • A fungal infection (thrush mouth)
  • Lichen planus

If there is no underlying cause of white patches, the healthcare provider may take a tissue sample and do a biopsy. If no causative factor is identified during the biopsy, the cause of the white spots in the mouth may be deemed leukoplakia. This indicates that the white spots have a possibility of becoming cancerous.

Note: If a dentist is the first to discover the white spots in the mouth, it's likely that a consultation may be made to a medical doctor to formulate the diagnosis and for subsequent treatment (after ruling out other causes).


Oral leukoplakia often will resolve on its own, once the causative irritation (such as tobacco or alcohol use) is removed. It may take several weeks, or up to months, for leukoplakia to resolve itself.

Treatment of leukoplakia is aimed at preventing cancer. The white patches are often removed, but often they will spontaneously reappear. Other forms of intervention for the treatment of leukoplakia include:

  • Preventive measures, like stopping the use of all tobacco as well as ceasing to ingest any alcohol
  • A change in diet, including the addition of many different types of fruits and vegetables each day
  • Administration of topical vitamin A (retinoids)
  • Administration of oral (by mouth) supplements of vitamin A and beta-carotene (this often helps to clear up the white patches, but they often return once vitamin A is no longer being taken)
  • Isotretinoin supplements (a synthetic derivative of vitamin A)
  • Surgical removal of lesions
  • Laser or photodynamic removal of lesions
  • Cryotherapy
  • Electrocauterization


Prevention measures to keep leukoplakia at bay may include:

  • Avoiding tobacco use
  • Maintaining good oral hygiene
  • Selecting the proper toothbrush
  • Seeking medical advice when white spots initially appear in the mouth
  • Following your doctor’s instructions

A Word From Verywell

As with most types of cancer, early intervention is the key to effective treatment. If you notice any type of oral white spots, be sure to consult with your healthcare provider as soon as possible.

Frequently Asked Questions

  • When should I be worried about white spots in my mouth?

    In most cases, white spots in the mouth are temporary, harmless, and can be treated. White spots due to leukoplakia, however, can turn cancerous.

    Leukoplakia involves one or more white patches in the mouth that cannot be wiped off. White patches can appear inside the cheeks, behind the lip, or on or under the tongue. They are not painful and do not have any other symptoms. 

    If you see a white patch in your mouth that cannot be wiped off and does not go away after a few days, make an appointment to see a dentist to have it checked out. 

  • What are these little white bumps on my tongue?

    A tiny white bump or bumps on the tongue's upper surface is a condition known as transient lingual papillitis. Often referred to as lie bumps, they are an inflammation of fungiform papillae—the flat, pink bumps on the top and sides of the tongue. 

    Lie bumps can be caused by something you ate or drank that was too hot, spicy, or acidic. The spots can also be from trauma (i.e., biting your tongue), poor nutrition, underlying infection, stress, hormonal fluctuations, or food allergy. 

  • Can you pop a white bump in your mouth?

    No. Do not try to pop a white bump in your mouth. Attempting to pop a spot in your mouth will only cause further injury and prolong the healing process. For the most part, a white pump in your mouth should heal on its own in a few days to a week, depending on the cause.

4 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
  1. Cleveland Clinic. Leukoplakia.

  2. Carrard V, van der Waal I. A clinical diagnosis of oral leukoplakia; A guide for dentists. Med Oral. :0-0. doi:10.4317/medoral.22292

  3. University of Florida. Leukoplakia.

  4. Kuribayashi Y, Tsushima F, Morita K, et al. Long-term outcome of non-surgical treatment in patients with oral leukoplakiaOral Oncology. 2015;51(11):1020-1025. doi:10.1016/j.oraloncology.2015.09.004

By Sherry Christiansen
Sherry Christiansen is a medical writer with a healthcare background. She has worked in the hospital setting and collaborated on Alzheimer's research.