Oral Thrush
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Oral Thrush: Symptoms, Causes & Treatments

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Medically Reviewed By Colgate Global Scientific Communications

You can experience mouth discomfort from time to time. It can manifest as white patches or cause soreness similar to an oral thrush. While seeking professional help is recommended, patience and care can go a long way. Gentleness to the area and mindful attention while waiting for an appointment may provide some relief. With a little caution, many common mouth issues eventually clear up.

What is Oral Thrush?

Oral thrush, or oral candidiasis, is a fungal infection in the mouth caused by the yeast Candida albicans, making it an infectious disease. It appears as white, sometimes painful, lesions on the tongue or inner cheeks, and it can spread to other mouth areas and even to the esophagus in severe cases. It’s common in babies and those with compromised immunity, and it can affect anyone.

Symptoms of Oral Thrush

Early-stage oral thrush may not show symptoms. However, as it progresses, several key changes may emerge:

  • Creamy white patches on the tongue, inner cheeks, gums, or tonsils. These patches resemble cottage cheese and cannot be easily rubbed off.

  • Discomfort or pain, especially during eating or drinking.

  • Potential bleeding upon scraping the patches.

  • Dry, cracked skin at the corners of the mouth, particularly common in people who wear dentures.

  • An altered taste sensation, loss of taste, or a cottony feeling in the mouth.

  • Difficulty swallowing in severe cases is due to the spread to the esophagus. 

In severe cases, the white lesions can extend into your esophagus, which potentially makes swallowing difficult or causes a sensation similar to food being stuck in your throat.

Special Cases

In addition to the distinctive white mouth lesions, oral thrush in infants can cause feeding difficulties or fussiness. It can also pass the infection on to breastfeeding mothers. Mothers whose breasts are infected with candida may experience the following signs and symptoms:

  • Unusually red, sensitive or itchy nipples

  • Shiny or flaky skin on the darker, circular area around the nipple (areola)

  • Unusual pain during nursing or painful nipples between feedings

  • Stabbing pains deep within the breast

What Causes Oral Thrush?

Oral thrush occurs when the balance of Candida is disrupted by weak immunity, certain medications, or health conditions, leading to an outbreak. Oral thrush causes include:

  • Medications: Antibiotics, inhaled corticosteroids, and immune-suppressing medications can increase the risk of thrush by killing off good bacteria that keep Candida in check.

  • Dentures: The yeast can overgrow under ill-fitting dentures. Cleaning dentures regularly helps prevent a condition similar to thrush called denture stomatitis.

  • Dry mouth: Saliva contains substances that control fungi. A dry mouth from certain medications, health conditions, or ageing can increase the risk of thrush on the tongue or in the mouth.

  • Weakened immune system: Medical conditions like HIV/AIDS, cancer treatments, or diabetes can compromise the immune system and allow Candida to multiply.

  • Infants: Babies can develop thrush because of their underdeveloped immune systems. Breastfeeding infants can also pick up excess yeast from their mothers.

  • Poor oral hygiene: Not properly brushing and flossing allows Candida to flourish.

  • High-sugar diet: Candida thrives on sugar. A diet high in sweets and refined carbs can encourage fungal overgrowth.

What Are The Risk Factors of Oral Thrush? 

Below are the various factors that can contribute to an imbalance of Candida.

Weakened immunity:


  • Cancer and its treatments (chemotherapy, radiation)

  • Leukemia

  • Uncontrolled diabetes

  • Immunosuppressant medications

Age and oral healthcare:

  • Babies and infants

  • Older adults with reduced immunity or salivary flow

  • Dry mouth conditions

Habits and practices:

  • Smoking

  • Poor oral hygiene

  • Ill-fitting or unclean dentures

  • Broad-spectrum antibiotics (disrupting mouth bacteria)

  • Inhaled corticosteroids (increasing Candida presence)

What Are The Complications of Oral Thrush?

For individuals with compromised immune systems, oral thrush can be a bigger concern as it can spread more widely.

Some potential complications of oral thrush include:

  • Spreading infection: In people with a weakened immune system, thrush in the mouth can spread to the esophagus or other parts of your body. 

  • Difficulty eating or drinking: Lesions in the mouth or throat can make eating and drinking challenging and painful. This can contribute to nutritional deficiencies, especially in infants.

  • Difficulty talking: If thrush spreads to the throat and voice box, it can cause hoarseness or loss of voice.

  • Increased risk of infection: Thrush breaks down the tissues of the mouth, making it easier for bacteria and viruses to penetrate and cause more serious illness.

  • Absorption of medications: Thrush lesions can impede the proper absorption of drugs taken by mouth.

  • Spread to others: In rare cases, oral thrush can be passed to others through saliva. This is more likely for those with weakened immune systems.

  • Recurrence: If the root cause is not addressed, thrush is likely to return after treatment. Recurring infections make complications more probable.


Oral thrush is diagnosed through a physical exam of the mouth. The healthcare provider looks for the characteristic white lesions on the tongue, inner cheeks, gums, or other areas.

Here are the main ways oral thrush is diagnosed:

  • Physical exam: The doctor will examine the white lesions and plaques in the mouth visually to identify signs of thrush. Scraping the lesions causes minor bleeding points to thrush.

  • Microscopic exam: A sample from the lesions may be examined under a microscope to look for excess Candida yeast cells.

If thrush has extended deeper into the esophagus, additional tests may be done:

  • Culture test: Swab of the plaque may be cultured in the lab to confirm the overgrowth of Candida infection.

  • DNA probe test: A sample is taken, and a DNA probe is used to detect the presence of Candida fungus.

  • Blood test: A complete blood count may be done to check for nutritional deficiencies or other conditions like diabetes that predispose to thrush.

  • Biopsy: In chronic cases, a minor surgery to remove a small part of the affected tissue for examination may be done.

  • Endoscopy: A flexible tube with a light and camera may be used to visually examine the inside of the body, especially in the digestive tract.

How To Treat Oral Thrush?

Treatment for oral thrush varies based on the severity and individual circumstances.

  • For Babies and Nursing Mothers: Antifungal medication can be prescribed for both. It's also essential to clean and sterilise all items they put in their mouth, like pacifiers, teethers, bottle nipples, and breast pump parts.

  • For Healthy Adults and Children: Eating unsweetened yoghurt or taking acidophilus can help rebalance mouth flora. Persistent infections may require antifungal medication.

  • For those with weak immune systems: Antifungal medications or, in resistant cases, Amphotericin B might be administered.

Mild cases:

  • Over-the-counter antifungal medications: These come in gels, lozenges, or liquids you swish and swallow. Common options include miconazole or nystatin.

  • Probiotics: Yoghurt with live cultures or probiotic supplements may help restore good bacteria in your mouth, though the evidence is mixed.

Severe cases or underlying conditions:

  • Prescription antifungal medications: These might be tablets, lozenges, or liquids, depending on the specific medication.

  • Addressing underlying conditions: Treating diabetes, managing HIV/AIDS, or adjusting medications that contribute to thrush can be crucial.

  • Dental visit: If symptoms worsen, do not improve within a few weeks, or you have concerns, consult your dental professional.

Home Remedies

Oral thrush can be treated at home using natural ingredients with antifungal properties. Some home remedies that can help relieve symptoms and supplement treatment include:

  • Coconut oil: Swish with a teaspoon of organic virgin coconut oil daily to help kill yeast overgrowth.

  • Aloe vera: The inner gel has antifungal effects. Apply directly to lesions several times a day.

  • Proper oral hygiene: Brush your teeth twice daily and clean dentures to help remove excess Candida over time.

  • Saltwater Rinse: Dissolve 1/2 teaspoon salt in 1 cup of warm water. Swish and spit out.

  • Yoghourt: Eat unsweetened yoghurt for probiotics or take a daily probiotic supplement.

  • Lemon Juice: Mix lemon juice from 1/2 lemon into 1 cup water. Drink or use as a mouthwash.

How Do You Prevent Oral Thrush?

Preventing oral thrush involves adopting proactive measures to maintain oral health and minimize the risk of fungal infections. From addressing specific medication practices to dietary considerations and overall hygiene, here are key strategies to help prevent the occurrence of oral thrush.

  • Rinse your mouth if you are using a corticosteroid inhaler.

  • Consume fresh-culture yoghurt when on antibiotics.

  • Address vaginal yeast infections promptly during pregnancy.

  • Regular dental check-ups are crucial.

  • Reduce intake of foods rich in sugar and yeast.

Good oral hygiene and prompt medical advice can clear up most thrush cases. Controlling any underlying medical conditions is also important in preventing recurrent infections. Though uncomfortable, oral thrush is curable with the right care.