Oral thrush is a fungal infection of the mouth caused by an overgrowth of Candida, a yeast that lives harmlessly in most people's mouths until something tips the balance. The classic sign is creamy white patches on the tongue, inner cheeks, or palate that can be wiped away to leave a red, tender surface. It is common, treatable, and usually a signal that something else has changed, such as a course of antibiotics, a dry mouth, or a denture that needs better cleaning.
This guide covers what oral thrush looks like, who tends to get it, how it is treated, and when the patches in your mouth need a closer look.
Key takeaways
- Oral thrush is an overgrowth of Candida yeast, not a sign of poor hygiene alone.
- The hallmark is white patches that wipe off to reveal a red, sometimes bleeding, base.
- Common triggers include antibiotics, inhaled steroids, dry mouth, dentures, diabetes, and a weakened immune system.
- Mild cases respond to antifungal gels or rinses; persistent cases may need a tablet such as fluconazole.
- White patches that do not wipe off, or that keep coming back, should be checked, since other conditions can look similar.
What oral thrush looks and feels like
The most recognisable form is creamy white, slightly raised patches that resemble cottage cheese. Unlike many other white patches in the mouth, these can be gently wiped off, leaving a red and sometimes sore area underneath. Other signs include:
- A burning or sore feeling, especially when eating or drinking
- Loss of taste or a cottony feeling in the mouth
- Redness and cracking at the corners of the mouth
- Red, inflamed tissue under an upper denture
Not every case shows the classic white patches. A form called erythematous candidiasis appears as smooth red areas, often on the tongue or palate, without the white film. This is one reason a professional assessment helps.
What causes oral thrush in adults
Healthy adults with a normal immune system do not usually get thrush without a reason. The infection tends to appear when the natural balance in the mouth is disturbed. Common contributors include:
- Antibiotics: they reduce the normal bacteria that keep Candida in check.
- Inhaled corticosteroids: common in asthma and COPD inhalers, especially when the mouth is not rinsed after use.
- Dry mouth: saliva helps control yeast, so a dry mouth from medications or other causes raises the risk. See dry mouth causes and treatment.
- Dentures: particularly when worn overnight or not cleaned well. This overlaps with denture stomatitis.
- Diabetes: higher glucose levels can encourage yeast growth, another reason gum and mouth health matter, as covered in diabetes and gum disease.
- A weakened immune system: from illness, chemotherapy, or long-term steroid use.
How oral thrush is treated
Treatment has two parts: clearing the infection and addressing whatever allowed it to take hold. The second part is what prevents it coming straight back.
Antifungal medication
Mild, localised thrush often responds to a topical antifungal such as a miconazole oral gel or a nystatin liquid that you swish around the mouth and then swallow, usually several times a day for one to two weeks. For more widespread or stubborn cases, or in people with a weakened immune system, a doctor or dentist may prescribe a tablet such as fluconazole, which research suggests is generally more effective than nystatin for clearing the infection. Always finish the full course, even once the patches clear, because stopping early invites a relapse.
Fixing the underlying trigger
This is the step people skip. Rinse your mouth with water after using a steroid inhaler. Take out and clean dentures every night and never sleep in them. Manage a dry mouth. Keep diabetes well controlled. Without this, thrush tends to return.
Self-care that helps
- Brush twice a day and clean your tongue gently.
- Soak dentures overnight in an appropriate cleaner and brush them daily.
- Rinse with water or a mild salt-water rinse, especially after inhalers.
- Limit sugary drinks and snacks, which feed yeast.
- Stay hydrated to support saliva flow.
When to see a dentist or doctor
See a professional if the patches do not improve within a week or two, keep returning, make eating or swallowing difficult, or appear alongside a weakened immune system. Crucially, a white patch that does not wipe off may not be thrush at all. Conditions such as oral lichen planus and leukoplakia and erythroplakia can look similar and need different management. Any white or red patch that lasts more than two weeks deserves assessment, which is the same rule we apply in oral cancer screening.
General cost of assessment in Australia
Diagnosis is usually based on a clinical look, sometimes with a simple swab. The ranges below are general market figures, not a quote.
| Service | Typical Australian range | Notes |
|---|---|---|
| Dental consultation | $60 to $130 | Examination and advice |
| Swab or sample (if needed) | $30 to $90 | To confirm the organism |
| Antifungal medication | $15 to $40 | Gel, rinse, or tablet course |
The team at Lumi Dental does not list its own prices here. For current options and a written quote, see our current offers or our general dentistry page.
Frequently asked questions
Is oral thrush contagious?
It is generally not considered contagious between healthy adults, since most people already carry Candida. It can be passed in specific situations, such as between a breastfeeding mother and baby, but for most adults it reflects an internal imbalance rather than catching it from someone.
Can I treat oral thrush at home?
Mild cases may settle with good mouth and denture care, and pharmacy antifungal gels can help. If it does not clear within a week or two, keeps returning, or you have a health condition that weakens immunity, see a dentist or doctor.
Why do I keep getting thrush?
Recurrence almost always means the underlying trigger is still there. Common culprits are an inhaler used without rinsing, dentures worn overnight, an unmanaged dry mouth, or blood sugar that is not well controlled.
How long does oral thrush take to clear?
With appropriate antifungal treatment, many cases improve within several days and clear within one to two weeks. Finishing the full course and fixing the trigger reduces the chance of it returning.
The bottom line
Oral thrush is common, treatable, and usually a clue that something has shifted in your mouth or general health. Clearing the yeast is the easy part. Lasting relief comes from finding and fixing the trigger. If you have sore white or red patches that are not settling, the team at Lumi Dental in Melrose Park can take a look and rule out anything that needs different care. See our current offers to book.
