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Oral Thrush: Symptoms, Causes, Risk Factors & Treatment Options

Alyssa Hill
Written by
Alyssa Hill
Medically Reviewed by 
Dr. Lara Coseo
5 Sources Cited

What is Oral Thrush?

Oral thrush (oral candidiasis) is a yeast infection that forms due to the overgrowth of Candida fungus.

The most common type of Candida fungus that causes thrush is Candida albicans. These fungi live in the mucous membranes lining the mouth. 

Most people have small traces of Candida in their mouths. In some cases, the fungi can overgrow and cause thrush. However, if you have a strong immune system, the fungus does not overgrow and you will not develop thrush.

Candidiasis most commonly affects people with weakened immune systems, such as infants or adults taking certain medications. Although, the condition can affect people of all ages.

Thrush is difficult to notice, at least at first, and does not cause severe pain. The condition is also uncomfortable to deal with on a daily basis. It typically doesn’t indicate a serious medical problem.

What Does Thrush Look Like?

Candidiasis is a widespread condition that creates white spots (lesions) that wipe off but leave a red, raw base. The lesions can either develop on the tongue, palate, or buccal mucosa (lining of the cheeks and back of the lips). The condition may also cause mild burning.

Pictures of Oral Thrush
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Symptoms of Oral Thrush

Thrush can cause some, or all, of the following symptoms:

  • White patches (lesions) that develop on the tongue, palate, cheeks, or inner lips
  • Sore mouth, lips, cheeks, tongue, or throat
  • Redness around the lesions
  • Dry or cracked lips
  • Soreness in the mouth
  • Decreased sense of taste
  • A burning sensation on the tongue or around the lesions
  • Cottonmouth or dry mouth
  • Severe oral thrush can reduce the ability to swallow, speak, and eat
  • Ill-fitting dentures — If you have thrush and also wear dentures, make sure you clean them every night

What Causes Oral Thrush?

Thrush can be triggered by a variety of factors, including existing medical conditions and poor oral health:


Antibiotics are commonly prescribed to sick patients to fight off harmful bacteria. However, children and adults taking antibiotics may develop thrush symptoms because the medications also temporarily kill harmless bacteria. Thus, weakened immune systems create a perfect environment for Candida fungus to thrive.

Dry Mouth

Dry mouth is an oral condition that occurs when the salivary glands in the mouth do not produce enough saliva to keep the mouth wet. Consequently, inadequate saliva production increases the risk of oral thrush.

Poor Oral Hygiene

Using an old toothbrush with harbored fungus can also cause thrush. It is recommended to switch toothbrushes or toothbrush tips at least every three months to prevent the spread of bacteria and fungus.

HSV-1 Infection

Herpes simplex virus type 1 (HSV-1) is a highly contagious infection that causes cold sores and may also cause mild candidiasis. HSV-1 is a lifelong disease that spreads through close personal contact, such as kissing, and sharing utensils.

Cancer Treatment

Oral thrush is the most common fungal infection cancer patients get while receiving treatment. Cancer treatments weaken the immune system, which can trigger the growth of Candida fungus.

Pregnancy & Yeast Infections

Pregnant women are at a higher risk of developing oral candidiasis. This is due to extreme changes in hormones. If a woman has a yeast infection while giving birth, the infection can also be transferred to the baby during labor.


Using steroid medications long-term can cause this condition. Moreover, if you frequently use an asthma inhaler that contains steroids, you have an increased risk of developing oral candidiasis.

Bottles and Pacifiers

Pacifiers and baby bottles can make a baby’s mouth too moist, creating the ideal environment for yeast to grow in. So, to help prevent oral candidiasis, babies should not go to sleep with a bottle in their mouths, and pacifier use should be limited throughout the day. In addition, thoroughly clean pacifiers and bottle nipples in the dishwasher or soak them in hot water after each use to remove bacteria and fungus.

The American Academy of Pediatrics recommends stopping pacifier use altogether after a baby turns 6 months old to prevent thrush, other oral conditions, and ear infections.

Uncontrolled Diabetes

High levels of glucose make it easier for Candida fungus to grow. More specifically, diabetics who do not monitor their blood sugar accurately have a higher risk of developing yeast infections.

Weakened Immune Systems

People who have diabetes, HIV/AIDS, or take steroid medications are also at risk of developing thrush. In these cases, thrush can be life-threatening.

Oral Thrush in Babies and Children

Babies and children are susceptible to developing candidiasis because they have decreased immunity. Infants, which refers to babies between 0 and 1 years of age, develop the condition most commonly.

Additionally, young children are more likely to develop the condition if they:

  • Have taken antibiotics due to sicknesses, such as strep throat or the flu
  • Do not clean orthodontic appliances before use
  • Use an inhaler for asthma
  • Have a weaker immune system than most children, which means they get sick easier
  • Frequently use a pacifier (babies)
  • Were born prematurely and had a low birth weight
  • If a mother has a vaginal yeast infection while giving birth, the baby can contract it during vaginal delivery

How Can I Get Rid of Oral Thrush Fast?

Thrush is a non-life-threatening infection that typically goes away within a few days to two weeks (severe cases) with proper treatment. If it doesn't resolve within this timeframe, contact your general dentist as soon as possible.

Treatment may include:

  • Antifungal Medication — kills bacterial funguses inside the mouth. Common medications used to treat thrush include miconazole, clotrimazole, nystatin, itraconazole, and fluconazole. They may come in the form of a tablet, a mouth rinse, or a lozenge.
  • Antiseptics — these medications prevent the growth of Candida fungus, while also killing harmful bacteria in your mouth.
  • Dietary Supplements — probiotics may be prescribed to support the growth of “healthy” bacteria.
  • Throat Lozenges — if oral thrush causes a sore throat, throat lozenges (cough drops) can be used to relieve discomfort. These medications can be bought directly at a drugstore without a prescription. They are also relatively inexpensive.

How Do You Prevent Oral Thrush?

The best way to prevent thrush is to practice good oral hygiene. Children and adults should brush their teeth at least twice a day with fluoridated toothpaste.

You should also visit a dentist every six months for teeth cleanings, use mouthwash regularly, and floss daily. Eating unsweetened yogurt can also reduce symptoms and discomfort of candida infections.

Is oral thrush contagious?

Oral thrush is a non-contagious fungal infection of the mouth.

Can oral thrush go away on its own?

Oral thrush can be mild and go away on its own within a few days. However, more severe cases may require anti-fungal medications and home remedies.

Can oral thrush make you feel unwell?

For most people, oral thrush does not cause any serious symptoms.

How long does it take for oral thrush to go away?

Thrush is a non-life-threatening infection that typically goes away within a few days to two weeks (severe cases) with proper treatment. If it doesn't resolve within this timeframe, contact your dentist as soon as possible.

What medication is best for oral thrush?

Common medications used to treat thrush include miconazole, clotrimazole, nystatin, itraconazole, and fluconazole. They may come in the form of a tablet, a mouth rinse, or a lozenge.

Last updated on January 7, 2022
5 Sources Cited
Last updated on January 7, 2022
All NewMouth content is medically reviewed and fact-checked by a licensed dentist or orthodontist to ensure the information is factual, current, and relevant.

We have strict sourcing guidelines and only cite from current scientific research, such as scholarly articles, dentistry textbooks, government agencies, and medical journals. This also includes information provided by the American Dental Association (ADA), the American Association of Orthodontics (AAO), and the American Academy of Pediatrics (AAP).
  1. “Candida Infections of the Mouth, Throat, and Esophagus | Fungal Diseases | CDC.” Centers for Disease Control and Prevention, Centers for Disease Control and Prevention,
  2. Oral thrush: Overview. Cologne, Germany: Institute for Quality and Efficiency in Health Care (IQWiG); 2006.
  3. “Oral Thrush.” Mayo Clinic, Mayo Foundation for Medical Education and Research, 8 Mar. 2018,
  4. Nowak, Arthur J. Pediatric Dentistry: Infancy through Adolescence. Elsevier, 2019.
  5. “Thrush (Oral Candida Infection) in Children.” Thrush (Oral Candida Infection) in Children - Health Encyclopedia - University of Rochester Medical Center,
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