If the white patches are scraped away, the area underneath will be red and may bleed. Occasionally, an oral yeast infection can cause the tongue to be red without a white coating.

Newborn babies, adult denture users, and people with endocrine disorders such as diabetes or hypothyroidism are the most at risk for oral yeast infections. Older adults often experience thrush under their dentures.

In AIDS patients, an infection called esophagitis may form in the upper digestive tract, and can be a serious health threat for these patients. This is an infection very similar to thrush, but it extends down from the mouth into the esophagus and stomach.

Thrush can be very painful and this can make it difficult to eat and drink, which can lead to dehydration. Any child that goes without drinking liquids for more than 12 hours should be taken to the doctor. The same care should be taken for elderly adults. Anyone with a compromised immune system must see a doctor immediately if they see the symptoms of an oral yeast infection.

Treating Oral Yeast Infections

Oral yeast infections are usually treated with antibiotics that require a prescription. Most symptoms go away soon after beginning an antifungal medication, and if the infection is mild enough, it may even go away on its own.

Your doctor may be able to diagnose thrush by taking a look, but if in doubt she'll take a scrape from the infected area in the mouth and send it to the lab.

Oral infections that look a lot like thrush can be caused by other things - including the early stages of cancer. That makes a qualified diagnosis that much more important.

The first step in treatment will be to get rid of the yeast, and this is usually done with prescription antifungal medication in a form that can be sucked or as a liquid that is held in the mouth before swallowing. Medications that may be prescribed include nystatin (Mycostatin) and fluconazole (Diflucan).

If the infection spreads because your immune system has been compromised, your doctor will use a systemic treatment that is taken orally or intravenously, and treat the infection very aggressively.

According to the Mayo Clinic, some oral yeast infections require no medical treatment at all because they go away on their own. For instance, healthy toddlers may get thrush after being treated with antibiotics. Your child's doctor may suggest that you add unsweetened yogurt to your child's diet because yogurt contains beneficial bacteria. If this doesn't help, your child's doctor will prescribe an antifungal medication.

Healthy adults can also try eating yogurt, or take a dietary supplement that includes the good bacteria called acidophilus. This may restore the microbial balance, but if it doesn't work a prescription will be needed.

The second step in treating oral yeast infections is to correct any condition that may have caused it. Dentures will need to be treated to destroy the fungus and ill-fitting dentures may need to be repaired or replaced. If the patient is diabetic, an adjustment may be needed in the diabetic medications that are being taken.

Since a high-sugar diet is known to cause oral yeast infections, a change in diet should always be considered in addition to any other treatment for thrush.

If an infant who is breast feeding gets thrush, the mother will also be treated to keep the infection from being passed back and forth between mother and child.