Thrush is a yeast infection of the tongue and lining of the mouth.
Certain germs normally live in our bodies. This includes bacteria and fungi. While most germs are harmless, some can cause infection.
Thrush occurs in children and adults when too much of a fungus called Candida grows in your mouth. A small amount of this fungus normally lives in your mouth. It is usually kept in check by your immune system and other germs that also live in your mouth.
When your immune system is weak or when normal bacteria die, too much of the fungus can grow.
You are more likely to get thrush if:
- You are in poor health.
- You are very old. Young babies are also more likely to develop thrush.
- You have HIV or AIDS.
- You are receiving chemotherapy or drugs that weaken the immune system.
- You are taking steroid medicine, including some inhalers for asthma and COPD.
- You have diabetes and your blood sugar is high. When your blood sugar is high, some of the extra sugar is found in your saliva and acts as food for Candida.
- You take antibiotics. Antibiotics kill some of the healthy bacteria that keep Candida from growing too much.
- Your dentures don't fit well.
Candida can also cause yeast infections in the vagina.
Symptoms of thrush include:
- White, velvety sores in the mouth and on the tongue
- Some bleeding when you brush your teeth or scrape the sores
- Pain when swallowing
Exams and Tests
Your doctor or dentist can usually diagnose thrush by looking at your mouth and tongue. The sores are easy to recognize.
To confirm you have thrush, your doctor may:
- Take a sample of a mouth sore by gently scraping it
- Examine mouth scrapings under a microscope
In severe cases, thrush can grow in your esophagus as well. The esophagus is the tube that connects your mouth to your stomach. If this occurs, your doctor may:
- Take a throat culture to see what germs are causing your thrush
- Examine your esophagus and stomach with a flexible, lighted scope with a camera on the end
If you get mild thrush after taking antibiotics, eat yogurt or take over-the-counter acidophilus pills. This may help restore a healthy balance of germs in your mouth.
For a more severe case of thrush, your doctor may prescribe:
- Antifungal mouthwash (nystatin)
- Lozenges (clotrimazole)
- Antifungal medicines taken as a pill or syrup - These medicines include fluconazole (Diflucan) or itraconazole (Sporanox).
Oral thrush can be cured. However, if your immune system is weak, thrush may come back or cause more serious problems.
When to Contact a Medical Professional
Call your doctor if:
- You have thrush-like sores
- You have pain or difficulty swallowing
- You have symptoms of thrush and you are HIV positive, receiving chemotherapy, or you take medications to suppress your immune system
If you get thrush often, your doctor may recommend taking antifungal medication on a regular basis to keep thrush from coming back.
If you have diabetes, you can help prevent thrush by keeping good control of your blood sugar levels.
Candidiasis - oral; Oral thrush; Fungal infection - mouth; Candida - oral
Edwards JE Jr. Candida species. In: Mandell GL, Bennett JE, Dolin R, eds.Principles and Practice of Infectious Diseases
Kauffman CA. Candidiasis. In: Goldman L, Schafer AI, eds.Goldman's Cecil Medicine
Update Date 9/1/2013
Updated by: Jatin M. Vyas, MD, PhD, Assistant Professor in Medicine, Harvard Medical School; Assistant in Medicine, Division of Infectious Disease, Department of Medicine, Massachusetts General Hospital. Also reviewed by David Zieve, MD, MHA, Bethanne Black, and the A.D.A.M. Editorial team.