Oral thrush happens when a yeast infection develops inside your mouth. It’s also known as oral candidiasis, oropharyngeal candidiasis, or simply thrush.

Oral thrush most often occurs in infants and toddlers. It causes white or yellowish bumps to form on the inner cheeks and tongue. Those bumps usually go away with treatment.

The infection is typically mild and rarely causes serious problems. But in people with weakened immune systems, it can spread to other parts of the body and cause potentially serious complications.

In its early stages, oral thrush may not cause any symptoms. But as the infection gets worse, one or more of the following symptoms may develop:

In some cases, oral thrush can affect your esophagus, though this is uncommon. The same fungus that causes oral thrush can also cause yeast infections in other parts of your body. Learn more about the symptoms of oral thrush and other types of yeast infections.

Oral thrush and other yeast infections are caused by an overgrowth of the fungus Candida albicans (C. albicans).

It’s normal for a small amount of C. albicans to live in your mouth, without causing harm. When your immune system is working properly, beneficial bacteria in your body help keep C. albicans under control.

But if your immune system is compromised or the balance of microorganisms in your body is disrupted, the fungus can grow out of control.

You may develop an overgrowth of C. albicans that causes oral thrush if you take certain medications that reduce the number of friendly microorganisms in your body, such as antibiotics.

Cancer treatments, including chemotherapy and radiation therapy, can also damage or kill healthy cells. This makes you more susceptible to oral thrush and other infections.

Conditions that weaken your immune system, such as leukemia and HIV, also increase the risk of developing oral thrush. Oral thrush is a common opportunistic infection in people with HIV.

Diabetes can contribute to oral thrush as well. Uncontrolled diabetes weakens your immune system and causes high blood sugar levels. This creates favorable conditions for C. albicans to grow.

If you have oral thrush, it’s possible to pass the fungus that causes this condition on to someone else if you kiss them. In some cases, that person might develop oral thrush.

The fungus that causes oral thrush also causes yeast infections in other body parts. It’s possible for you to pass the fungus from one part of your body to another part of someone else’s body.

If you have oral thrush, a vaginal yeast infection, or a penile yeast infection, you can potentially pass the fungus to your partner through vaginal sex, anal sex, or oral sex.

If you’re pregnant and you have a vaginal yeast infection, you can potentially pass the fungus to your baby during delivery.

If you have a breast yeast infection or nipple yeast infection, you can pass the fungus to your baby while breastfeeding. Your baby can also transmit the fungus to you if they breastfeed when they have oral thrush.

When C. albicans is passed from one person to another, it doesn’t always cause oral thrush or other types of yeast infection.

Also, because C. albicans is so common in our environment, developing a yeast infection does not mean you necessarily caught it from someone else. Learn about some of the factors that can raise your risk of developing an infection when someone passes this fungus to you.

Your doctor may be able to diagnose oral thrush simply by examining your mouth for the characteristic bumps that it causes.

In some cases, your doctor may take a biopsy of the affected area to confirm the diagnosis. To perform a biopsy, they will scrape off a small portion of a bump from your mouth. The sample will then be sent to a laboratory to be tested for C. albicans.

If your doctor suspects that you have oral thrush in your esophagus, they may use a throat swab culture or endoscopy to confirm the diagnosis.

To perform a throat swab culture, your doctor uses a cotton swab to take a tissue sample from the back of your throat. They then send this sample to a laboratory for testing.

To perform endoscopy, your doctor uses a thin tube with a light and camera attached to it. They insert this “endoscope” through your mouth and into your esophagus to examine it. They may also remove a sample of tissue for analysis.

To treat oral thrush, your doctor may prescribe one or more of the following medications:

  • fluconazole (Diflucan), an oral antifungal medication
  • clotrimazole (Mycelex Troche), an antifungal medication that’s available as a lozenge
  • nystatin (Nystop, Nyata), an antifungal mouthwash that you can swish in your mouth or swab in your baby’s mouth
  • itraconazole (Sporanox), an oral antifungal medication that’s used to treat people who don’t respond to other treatments for oral thrush and people with HIV
  • amphotericin B (AmBisome, Fungizone), a medication that’s used to treat severe cases of oral thrush

Once you begin treatment, oral thrush usually goes away within a couple of weeks. But in some cases, it can return.

For adults who have recurring cases of oral thrush with no known cause, their healthcare provider will evaluate them for underlying medical conditions that might be contributing to thrush.

Infants may have several episodes of oral thrush in their first year of life.

Your doctor might also recommend home remedies or lifestyle changes to help treat oral thrush or stop it from coming back.

When you’re recovering, it’s important to practice good oral hygiene. Here are a few tips:

  • Brush your teeth with a soft toothbrush to avoid scraping the bumps caused by thrush.
  • Replace your toothbrush after you finish your treatment for oral thrush, and properly clean your dentures if you wear them, in order to lower your risk of reinfection.
  • Avoid mouthwashes or mouth sprays, unless your doctor has prescribed them.

Some home remedies may also help relieve symptoms of thrush in adults.

For example, it might help to rinse your mouth with one of the following:

  • saltwater
  • a solution of water and baking soda
  • a mixture of water and lemon juice
  • a mixture of water and apple cider vinegar

It might also help to eat yogurt that contains beneficial bacteria or take a probiotic supplement. Talk to a doctor before giving an infant any supplements. To learn more about these home remedies and others, click here.

The same fungus that causes oral thrush can also cause yeast infections on your breasts and nipples.

This fungus can be passed back and forth between mothers and babies during breastfeeding.

If your baby has oral thrush, they can potentially pass the fungus to your breasts or other areas of skin. If you have a breast yeast infection or nipple yeast infection, you can potentially pass the fungus to your baby’s mouth or skin.

Also, because yeast can live on the skin without causing an infection, your baby can develop oral thrush without you having any symptoms of a breast or nipple yeast infection.

If you develop a yeast infection on your breasts or nipples, you may experience:

If your baby develops oral thrush or you develop a breast or nipple yeast infection, it’s important to get treatment for both you and your baby. This can help prevent a cycle of transmission.

Your healthcare provider may advise you to do the following:

  • Treat your baby with an antifungal medication and apply an antifungal cream, such as terbinafine (Lamisil) or clotrimazole (Lotrimin), to your breasts. Wipe the cream off your breasts before breastfeeding your baby to stop the cream from getting in their mouth.
  • Sterilize your baby’s pacifiers, teething rings, bottle nipples, and any other items they put in their mouth. If you use a breast pump, sterilize all of its pieces as well.
  • Keep your nipples clean and dry between feedings. If you use nursing pads, avoid those that have a plastic liner, which may trap moisture and create favorable conditions for fungus to grow.

Your doctor might also advise you to make lifestyle changes to help treat or prevent oral thrush and other types of yeast infection. Get more tips for managing the risk of yeast infection while breastfeeding.

Oral thrush most often affects infants and toddlers. Babies can potentially develop oral thrush after contracting the fungus from their mothers during pregnancy, delivery, or breastfeeding or just from yeast that is naturally present in their environment.

If your baby has oral thrush, they may develop the same signs and symptoms that can affect other people with the condition, including:

Oral thrush in babies may also cause difficulty feeding and irritability or fussiness.

If you suspect that your baby might have oral thrush, make an appointment with their doctor. If your baby develops oral thrush while you’re breastfeeding them, both of you will need antifungal treatments. Find out why this is important for keeping you and your baby healthy.

Oral thrush is most common in babies and older adults, who tend to have weaker immune systems. But it can occur at any age.

Younger adults can develop oral thrush, especially if they have an impaired immune system. For example, adults are more likely to develop thrush if they have a history of certain medical conditions, medical treatments, or lifestyle habits that weaken their immune system.

In otherwise healthy adults, oral thrush is unlikely to cause serious problems. But if your immune system isn’t working well, the infection may spread to other parts of your body.

Babies, toddlers, and older adults are more likely than others to develop oral thrush. Certain medical conditions, medical treatments, and lifestyle factors can also increase your risk of thrush by weakening your immune system or disrupting the balance of microbes in your body.

For example, you may be at heightened risk of thrush if you:

In people with healthy immune systems, oral thrush rarely causes complications. In severe cases, it may spread to your esophagus.

If your immune system is weakened, you’re more likely to develop complications from thrush. Without proper treatment, the fungus that causes thrush may enter your bloodstream and spread to your heart, brain, eyes, or other body parts. This is known as invasive or systemic candidiasis.

Systemic candidiasis can cause problems in the organs it affects. It can also cause a potentially life-threatening condition known as septic shock.

To reduce your risk of oral thrush, try the following:

If you develop a yeast infection in another part of your body, get treatment. In some cases, an infection can spread from one part of your body to another.

More research is needed to learn how diet may affect oral thrush.

Some studies suggest that eating certain probiotic foods or taking probiotic supplements might help limit the growth of C. albicans. However, more research is needed to learn about the role that probiotics might play in treating or preventing oral thrush.

Some people believe that limiting or avoiding certain foods may also help curb the growth of C. albicans. For example, some people have suggested that limiting refined carbohydrates and sugars can help treat or prevent oral thrush and other yeast infections.

The “candida diet” has been developed based on these beliefs. However, this diet lacks scientific support. Get more information about what this diet entails and the limits of the scientific evidence supporting it.