What Is Oral Thrush?

Imagine cottage cheese-looking lesions forming on your tongue, inner cheeks and throat, and you have the unpleasant idea of what oral thrush looks like. It’s a medical condition when the fungus Candida albicans concentrates on the lining of the mouth.

Robert Matlock, DDS, MAGD, of Matlock General Dentistry in Rogers, Ark., says many people have the Candida fungus that creates oral thrush, though luckily, maintaining healthy immune systems keeps oral thrush away.

“We have a lot of bugs like that,” says Dr. Matlock. “We will have it all the time, it’s just not active.” Roughly 40 percent of people have Candida in their mouths but will not have any issues and will not develop oral thrush.

The good news is that Matlock says oral thrush is fairly easy to spot on a patient and it is rarely painful. “It is more uncomfortable than painful,” he says, “but in a severe state, it can be painful.”

According to Mayo Clinic, oral thrush lesions will bleed once they are scraped and sometimes they will spread to the mouth’s roof, the gums and tonsils.

Michael Rayburn, DDS, of Rayburn General Dentistry in Newnan, Ga., says the severity of oral thrush depends on a person’s overall health. “It is irritating, it is sore and it itches,” Dr. Rayburn says. “That’s probably as bad as it gets unless you have something else compromising your immune system.”

Who Gets Oral Thrush and Why?

Oral thrush is common in people with weak immune systems and in those who use inhaled corticosteroids, which help control asthma.

Rayburn says oral thrush is mainly an opportunistic infection. He says people who have compromised immune systems as a result of diseases like diabetes are likely to develop oral thrush. Additionally, Rayburn says people who are also generally sick and taking antibiotics are also at risk. “Antibiotics wipe out all the bacteria and then all of a sudden you have a fungal infection,” he says.

Matlock says that though oral thrush is not an everyday occurrence, he’s seen it from time to time in his practice. Although anyone can develop oral thrush, he sees it more commonly among elderly people who use dentures.

However, oral thrush can present in both the young and the old. One in eight babies develop oral thrush within the first four weeks of life, and seven in 10 people who wear dentures develop the condition at some point in time, as well. According to Matlock, this is caused by an elder’s weakened immune system and a baby’s lack of one. “That’s why we recommend breast feeding over bottle feeding,” Matlock says, “because they pick up their immune system from parents.”

Matlock says no one is born with oral thrush but it is a “contact-type” condition. Vaginal thrush is another common condition, which can cause mothers to give their babies oral thrush during normal deliveries.

Sometimes, it is not as simple for dentists and doctors to figure out why someone develops oral thrush, which is an especially common situation with adolescents. In this instance, blood tests and physicals are performed.

What Happens When Someone Has Oral Thrush?

Oral thrush is generally considered to be a minor condition for healthy people. However, it can be less controllable and cause more serious side effects in those with weaker immune systems, such as cancer patients or people with HIV.

Up to half of HIV-positive people will develop oral thrush at some point. And more than 90 percent of those with advanced HIV (AIDS) will get it.

This is when oral thrush can become dangerous and can possibly spread to a person’s esophagus, lungs, liver and digestive tract, as reported by Mayo Clinic. On a more severe level, oral thrush can cause eating to be painful and may actually travel into the intestines, causing prevention of sufficient nutritional intake.