Oral Thrush: Treatment, Symptoms, Causes

By Jenell Decker, MD
Medically reviewed
November 24, 2021

If you notice slightly raised areas in your mouth that are white or yellow in color, you may have oral thrush.

Also referred to as oral candidiasis, oral thrush is a type of yeast infection where the fungus candida albicans accumulates on the lining of your mouth.

If left untreated, it can spread to other parts of the body like the lungs, liver, and skin. 

Oral thrush is common, but occurs more often in newborns in their first year of life and immunocompromised individuals, including patients battling cancer, HIV, and other diseases that attack the immune system.

In this article, I’ll describe the symptoms of oral thrush, and whether it’s contagious.

I’ll also outline its causes, and explain how it affects both adults and babies.

I’ll discuss risk factors for contracting oral thrush, its diagnosis, and treatment, including with at-home remedies. 

Oral Thrush Symptoms

In the early stages, there may be no symptoms of oral thrush.

As it develops, the following symptoms may manifest:

  • Slightly raised areas on your tongue, inner cheeks, tonsils, gums, lips, or back of the throat that are white or yellow in color
  • Cottage-cheese like appearance on raised spots
  • Slight bleeding if the bumps are scraped or agitated
  • Dry, cracked skin at the corners of your mouth
  • Soreness or burning in your mouth
  • Cotton-like feeling in the mouth
  • Bad taste in the mouth
  • Loss of taste

In extreme cases you may experience the following symptoms:

  • Difficulty swallowing, or a feeling that food is stuck in the throat
  • Fever
  • Tightness in the middle of the chest

Is Oral Thrush Contagious?

Oral thrush is not considered contagious, but it can be passed back and forth between at-risk individuals or from mother to infant while breastfeeding.

In otherwise healthy people, it is very unusual for thrush to be passed by kissing or other close contact.

This is because candida is already present in everyone’s mouth–it only becomes thrush when it overgrows.

You may contract oral thrush by performing unprotected oral sex on someone who has a vaginal yeast infection or male thrush.

This is because candida fungus also lives in the vagina and the penis.

The same is true for receiving oral sex from someone with oral thrush—candida can also exist in the oral cavity, which puts you at higher risk of developing a yeast infection.

Causes

Everyone has small amounts of the candida fungus in their mouths, digestive tracts, and skin.

However, stress, certain illnesses, and medications can trigger an overgrowth, throwing your candida levels off balance.

This can result in infections, including oral thrush.

Oral Thrush in Babies

Infants are especially susceptible to oral thrush, as they have fragile immune systems.

By wiping your baby’s gums regularly, making sure they do not take anything but water to bed, and sterilizing their pacifiers and bottles, you can help prevent your baby from developing oral thrush.

You can typically tell your baby is struggling with oral thrush if they do not want to feed or have a diaper rash.

Oral thrush and breastfeeding

Babies can pass oral thrush onto their mothers during breastfeeding.

This will result in the following symptoms for the mother:

  • Red, itchy nipples
  • Sensitive, shiny, or cracked skin on the nipple and areola
  • Painful nursing or nipple pain between feedings
  • Sharp, stabbing pains deeper in the breast

Oral Thrush in Adults

Oral thrush is more likely to develop in adults who have compromised immune systems due to illness or medications.

This usually presents as an inflamed red mouth with white patches that bleed when touched.

How Long Does Oral Thrush Last Without Treatment?

A mild case of oral thrush can clear up on its own without treatment.

With the right treatment, symptoms should improve within a few days.

Without any treatment, it can take between three to eight weeks to resolve itself. 

Risk Factors

You may be more at risk of an oral thrush infection if any of these apply to you:

  • Compromised immune system: Oral thrush is more likely to occur in infants and adults with weakened immune systems. Some medical conditions and treatments can suppress your immune system. HIV infection, cancer and its treatments, and organ transplantation can put you at a higher risk. 
  • Diabetes: If you have untreated or uncontrolled diabetes, your saliva may contain large amounts of sugar. This will encourage the growth of candida, which can put you at risk of oral thrush.
  • Medications: Medications such as antibiotics, birth control pills, and corticosteroids, can disturb the natural balance of microorganisms in your body. This can put you more at risk of oral thrush.  
  • Vaginal yeast infections: The same fungus that causes oral thrush also causes vaginal yeast infections. You can pass the infection to your baby.
  • Dentures: Wearing dentures, especially upper dentures, can increase the buildup of candida.  
  • Smoking: Cigarette smoke can affect saliva and oral microorganisms, making you more susceptible to oral thrush.
  • Pregnancy: Sudden hormone changes can cause oral thrush.

Diagnosis

Your doctor will diagnose oral thrush differently depending on where it is located.

If thrush is just in your mouth, your doctor or dentist may:

  • Examine your mouth to look at the lesions
  • Take a small sample of the lesions to examine under a microscope
  • In some cases, perform specific blood tests to determine any possible underlying medical condition that could be causing oral thrush

If thrush is in your esophagus, your doctor may do the following:

  • Biopsy: This involves scraping off a small portion of a bump using a cotton swab to obtain a tissue sample. The sample is then sent to a laboratory for analysis. A biopsy will help determine which bacteria or fungi are causing your symptoms.
  • Endoscopic Exam: In more severe cases where your doctor suspects you may have oral thrush of the esophagus, they will do an endoscopic exam to confirm the diagnosis. For this, your doctor will insert an “endoscope”, a thin tube with a light and camera attached, through your mouth and into your esophagus to examine it. They may also take a sample of tissue for testing to confirm this diagnosis.
  • Physical examination: In certain circumstances, a physical exam and specific blood tests may be necessary. This is to help the doctor determine if there is an underlying medical condition that could be causing thrush in the esophagus.

Treatment

Prescription medications

  • Fluconazole (Diflucan): an oral antifungal medication
  • Clotrimazole (Mycelex Troche): an antifungal medication that’s available as a lozenge
  • Nystatin (Nystop, Nyata): an antifungal powder that is safe for use in infants
  • Itraconazole (Sporanox): an oral antifungal medication suitable for those who do not respond to other treatments for oral thrush and people with HIV
  • Amphotericin B (AmBisome, Fungizone): a medication that’s used for more severe cases of oral thrush

Over-the-counter medications

If you or your child is experiencing a mild case of oral thrush, over-the-counter (OTC) medications are available from your local pharmacy.

Talk to your doctor or pharmacist before taking any OTC medications:

  • Acidophilus pills: These pills are probiotics, introducing another microorganism, Lactobacillus acidophilus, into the mouth. In research reviews, this has been found to restore a healthy balance of germs in your mouth and potentially have a beneficial effect on oral thrush.
  • Oral Rinse: Ideal for mild cases of oral thrush, these rinses can work for up to eight hours. Some recommend rinsing three times a day and gradually reducing it as symptoms improve.
  • Oral Spray: Oral sprays are alcohol-free and work to alleviate the burning pain from oral thrush as they lubricate the mouth.

Complications

Oral thrush that is left untreated can lead to serious systemic infections, especially in those with a weakened immune system.

If oral thrush spreads to your esophagus or other parts of the body, the fungi may penetrate deeper layers of tissue.

In rare cases, it could reach the circulatory system and cause sepsis, a potentially fatal blood infection.

Home Remedies

Home remedies can help treat oral thrush and prevent it from coming back.

Practicing good oral hygiene is extremely important.

Here are a few tips for adults treating their oral thrush:

  • Choose a soft-bristled toothbrush to avoid aggravating the bumps caused by thrush.
  • Gargle with salt water, which is a natural antiseptic.
  • Take a probiotic supplement, or introduce yogurt into your diet that contains beneficial bacteria.
  • Drink or gargle lemon juice, which has antiseptic and antifungal abilities.
  • Rinse your mouth regularly with a solution of water and baking soda, or a combination of water and apple cider vinegar, to combat the infection. Do this after eating or drinking medicine.

Once you begin treatment, you can expect oral thrush to go away in a few weeks.

Avoid recurrence by throwing out any products that may be contaminated with the infection, including your toothbrush.

If you wear dentures, deep clean them.

If symptoms persist, consult your doctor. For at-home remedies for infants, consult your pediatrician.

Prevention

Since oral thrush can recur after treatment, it is important you take preventative measures to avoid this.

Consider including these prevention tips into your daily routine to minimize risk:

  • Practice good dental hygiene: Brush your teeth twice daily and floss your teeth once daily. Remove your dentures at night and clean them thoroughly. Check with your dentist that your dentures are fitting properly and not causing irritation.
  • Sterilize your child’s pacifiers and bottles: Sterilize bottles after every use, and sterilize pacifiers regularly.
  • Treat dry mouth: If you experience dry mouth, talk to your doctor about ways you can treat this. 
  • Improve your diet: Limit the amount of sugary foods you eat, as this encourages the growth of candida.

How K Health Can Help

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Frequently Asked Questions

What does oral thrush look like?
Oral thrush manifests as a red, inflamed mouth with white or yellow raised areas that may bleed when scraped.
How long does oral thrush last?
With treatment, oral thrush should clear up in about two weeks. Without treatment, it may last up to eight weeks or longer. Monitor your symptoms and visit a doctor immediately if you believe it has spread to your esophagus, as this can cause more serious infection.
K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.

Jenell Decker, MD

Dr. Decker is a family medicine physician who completed her residency at East Carolina University School of Medicine. She graduated medical school from Marshall University School of Medicine.