What is thrush?

Thrush is a fungal (yeast) infection that can grow in your mouth, throat and other parts of your body. In your mouth thrush appears as a growth that can look like cottage cheese – white, raised lesions on your tongue and cheeks. The condition can quickly become irritated and cause mouth pain and redness.

Thrush is caused by the overgrowth of a type of fungus called Candida. Mouth and throat thrush is called oropharyngeal candidiasis.

A thrush infection is annoying but it’s generally a minor problem for healthy people and will clear up in a few weeks with antifungal treatment.

Who can get thrush and is it contagious (pass from person to person)?

While thrush can affect anyone, babies under 1 month old, toddlers, older adults and people with weakened immune systems (where symptoms can be harder to control) are at more risk. Thrush in the esophagus (swallowing tube) is one of the more common infections in people with HIV/AIDS.

Thrush can be contagious to those at risk (like people with weakened immune systems or are taking certain medications). In healthy people, it’s unusual for it to be passed on through kissing or other close contacts. In most cases, thrush isn’t considered particularly contagious but it can be transmitted.

If you’re worried about getting thrush from another person who has it, avoid coming into contact with their saliva (spit). It’s smart to wash your hands as often as possible if you’re near someone who has thrush.

Why is thrush a concern during breastfeeding?

Because infants are more at risk, getting or giving thrush during breastfeeding is a worry with many moms. It’s a common breastfeeding problem, and in some cases treatment can be tricky.

Babies with thrush can pass the infection to their mothers. When the infection in a baby’s mouth leads to sore throat and pain, they cry and are irritable during feeding. Mothers (especially if they’re taking antibiotics) may also develop thrush infections around the breasts and nipples and transmit it to their babies.

When both mom and baby develop thrush they should be treated for the condition at the same time to prevent an ongoing exchange of the infection.

Symptoms and Causes

What causes thrush?

Most people have small amounts of the Candida fungus in the mouth, digestive tract and skin. They are normally kept in check by other bacteria and microorganisms in the body. When illnesses, stress, or medications disturb this balance, the fungus grows out of control and causes thrush.

Medications that can make yeast flourish and cause infection include:

Candida infection is more likely to develop with:

  • Uncontrolled diabetes.
  • HIV infection.
  • Cancer.
  • Dry mouth.
  • Pregnancy (caused by the hormonal changes that occur with pregnancy).
  • Smoking.
  • Wearing dentures that don’t fit well.

What are the symptoms of thrush?

Thrush usually develops suddenly. A common sign is the presence of those creamy white, slightly raised lesions in your mouth — usually on your tongue or inner cheeks. They can also be seen on the roof of your mouth, gums, tonsils or back of your throat. Other symptoms may be:

  • Redness and soreness inside and at the corners of your mouth.
  • Loss of ability to taste.
  • Cottony feeling in your mouth.

The lesions can hurt and may bleed a little when you scrape them or brush your teeth. In severe cases, the lesions can spread into your esophagus and cause:

  • Pain or difficulty swallowing.
  • A feeling that food gets stuck in the throat or mid-chest area.
  • Fever, if the infection spreads beyond the esophagus.

Thrush can spread to other parts of the body, including the lungs, liver and skin. This happens more often in people with cancer, HIV or other conditions that weaken the immune system.

Diagnosis and Tests

How is thrush diagnosed?

Your health care provider can usually tell right away if you have thrush by looking for the distinctive white lesions on your mouth, tongue or checks. Lightly brushing the lesions away reveals a reddened, tender area that may bleed slightly. A microscopic exam of tissue from a lesion will confirm whether or not you have thrush (but a physical exam is not always necessary).

If thrush extends into your esophagus other tests may be needed. Your health care provider might:

  • Take a throat culture (swabbing the back of your throat with sterile cotton and studying the microorganisms under a microscope).
  • Perform an endoscopy of your esophagus, stomach, and small intestine (examining the lining of these body areas with a lighted camera mounted on the tip of a tube passed through these areas).
  • Take X-rays of your esophagus.

Management and Treatment

How is thrush treated?

Healthy kids and adults can be effectively treated for thrush. But the symptoms may be more severe and hard to treat in those with weakened immune systems.

Antifungal medications (like nystatin) are often prescribed to treat thrush. These medicines are available in tablets, lozenges or liquids that are usually "swished" around in your mouth before being swallowed. Usually, you need to take these medications for 10 to 14 days. Your health care provider will have a specific treatment approach designed for you based on your age and the cause of the infection.

The presence of Candida infection can be a symptom of other medical problems. Be sure to talk to your health care provider to look for these and set up a treatment plan if needed.


How can thrush be prevented?

You can do these things to help you avoid a case of thrush:

  • Follow good oral hygiene practices: Brush your teeth at least twice a day and floss at least once a day.
  • Avoid certain mouthwashes or sprays: These products can destroy the normal balance of microorganisms in your mouth. Talk to your dentist or doctor about which ones are safe to use.
  • See your dentist regularly: This is especially important if you have diabetes or wear dentures.
  • Limit the amount of sugar and yeast-containing foods you eat: Foods such as bread, beer and wine encourage Candida growth.
  • If you smoke, QUIT! Ask your doctor about ways to help you kick the habit.



  • The American Academy of Oral Medicine. Oral Yeast Infections (Thrush or Candidiasis) ( Accessed 11/18/2021.
  • Centers for Disease Control and Prevention. Oropharyngeal/Esophageal Candidiasis (“Thrush”) ( Accessed 11/18/2021.
  • Akpan A, Morgan R. Oral candidiasis. Postgraduate Medical Journal. 2002;78(922):455-459. doi:10.1136/pmj.78.922.455. ( Accessed 11/18/2021.
