You wake up and your mouth feels strange. There's a white coating on your tongue, maybe some soreness, and it's not going away after you brush your teeth. Sound familiar? That's most likely oral thrush.
The good news is that it's very common, easy to treat with certain medications, and once you know what causes oral thrush, it's easier to avoid. This guide breaks down everything you need to know about the condition.
What actually is oral thrush?
Oral thrush is a fungal infection inside your mouth. It's caused by a yeast called Candida albicans, which is actually present in most people's mouths all the time. Under normal circumstances, your immune system and the bacteria in your mouth keep it in check.
The problem starts when something upsets that balance. When Candida gets the chance to overgrow, it produces those characteristic white patches on your tongue, inner cheeks or the roof of your mouth. The patches look a bit like cottage cheese and may feel sore or leave a raw, red area if you wipe them off.
Oral thrush isn't contagious in the way a cold is. You already have the yeast in your mouth. It's not something you catch from someone else either, though it can sometimes pass between a breastfeeding mother and baby.
What causes oral thrush?
There's no single cause. Oral thrush happens when the conditions in your mouth shift in a way that lets Candida take hold. Here are the most common culprits.
Antibiotics
Antibiotics are great at killing the bacteria causing your infection, but they also wipe out the good bacteria in your mouth keeping Candida under control. It's an unfortunate side effect of taking antibiotics as they can't tell what is 'good' and 'bad' bacteria.
Thrush often shows up mid-way through or just after a course of antibiotics, especially if you've been taking them for a while.
Steroid inhalers
If you use an inhaler for asthma or a lung condition, you're at a higher risk of oral thrush. The steroid particles from the inhaler can settle in your mouth and throat, creating a warm, sugary environment that Candida thrives in.
Rinsing your mouth with water every single time you use your inhaler helps remove those particles and make it harder for Candida to multiply.
A weakened immune system
Your immune system keeps Candida from getting out of hand in the first place. Anything that weakens it, whether that's an illness or a period of high stress, can give thrush the chance to develop.
If you keep getting oral thrush and can't identify any obvious trigger, it's worth seeing your GP to rule out an underlying condition.
Dentures
Dentures create a warm and snug environment against your gum tissue. If they don't fit well, or aren't cleaned properly every night, they can become an ideal breeding ground for Candida.
This is why oral thrush can be common in older adults. If you wear dentures, make sure you take them out at night, clean them thoroughly, and soak them in a sterilising solution.
Dry mouth
Saliva is your mouth's natural defence system. It washes away bacteria and yeast and helps maintain the right pH balance.
A dry mouth, whether it's from not drinking enough water or the side effects of medication, makes thrush far more likely.
Smoking
Smoking changes the environment inside your mouth in ways that favour Candida growth. It also suppresses the immune response of oral tissues.
Smokers are significantly more likely to develop oral thrush than non-smokers, and more likely to have repeated episodes.
Being a baby or older adult
Immune systems at the very start and end of life aren't as robust as they are in the middle years. Oral thrush is extremely common in babies under a year old and is usually nothing to worry about. In older adults, it tends to be linked to dentures, dry mouth, or medications rather than age alone.
If you keep getting oral thrush with no obvious trigger and you're not on antibiotics or steroids, book an appointment with your GP. It can occasionally be an early sign of diabetes or an immune deficiency that hasn't been picked up yet.
How do you know it is oral thrush?
The most obvious sign is white or cream-coloured patches on your tongue or inside your cheeks. They look a bit like milk residue or cottage cheese. Unlike a regular coated tongue, these patches don't brush off easily and leave behind a sore, red patch if you do wipe them away.
Other signs to look out for include:
- a burning or sore feeling inside your mouth, especially when eating
- redness or cracking at the corners of your mouth
- loss of taste, or food tasting different than usual
- a cottonwool-like feeling that doesn't go away
- difficulty swallowing in more severe cases
If you're not sure whether it's thrush or something else, a pharmacist can usually tell from a visual inspection or from a description of the symptoms.
How to treat oral thrush
Oral thrush doesn't tend to clear up on its own in adults. You'll likely need an antifungal treatment to tackle it. An effective and convenient option is an antifungal gel applied directly inside the mouth.
Daktarin Oral Gel contains miconazole, an antifungal ingredient that targets the Candida yeast and stops it reproducing. It's sugar-free, orange-flavoured, and available without a prescription from Pharmica.
How to use it correctly
- Apply 2.5ml (half a measuring spoon) to the affected area four times a day, after meals
- Hold the gel against the affected area for as long as possible before swallowing. Do not rinse your mouth straight after
- If you wear dentures, apply the gel directly to them at night whilst they are removed
- Continue for the full seven days even if symptoms clear up sooner. Stopping early is one of the main reasons oral thrush comes back
If you take warfarin, speak to your pharmacist before using Daktarin Oral Gel. Miconazole can strengthen the effect of warfarin significantly. It's also worth checking with a pharmacist if you're pregnant or breastfeeding.
When you might need something stronger
If the gel hasn't worked after seven days, or if the infection is severe or has spread, your GP may prescribe fluconazole tablets. These are taken orally and work throughout the body rather than just at the surface. They're typically reserved for more stubborn or widespread cases.
How to help stop oral thrush coming back
For a lot of people, a single course of treatment is enough. But if thrush keeps coming back, it could be down to lifestyle habits making it more likely to reoccur.
- Cut back on sugar. Candida feeds on it, so a high-sugar diet creates the ideal conditions for it to thrive.
- Stay hydrated. Keeping your mouth moist maintains its natural defences.
- Be cautious with antibiotics. Only take them when necessary. If you have to take a course, consider a probiotic alongside it to help restore your oral bacteria.
- Stop smoking. If you're a smoker, quitting is one of the biggest changes you can make for both your oral and overall health.
- Rinse your mouth after every single inhaler use, if you're prescribed one.
- Clean dentures every night. Soak them in a sterilising solution and remove them before sleep.
Frequently asked questions
Can oral thrush go away without treatment?
In adults, rarely. Thrush in a healthy baby might resolve on its own, but in adults, the Candida overgrowth doesn't tend to resolve itself without an antifungal.
Is oral thrush a sign of something serious?
In most cases, no. It's usually a straightforward reaction to antibiotics, an inhaler, or a temporary dip in immunity. If you keep getting it repeatedly with no obvious cause, it's worth a GP check to rule out diabetes or an immune condition.
Can you pass oral thrush to a partner?
In healthy adults, oral thrush isn't considered contagious through normal contact. The yeast involved is already present in most people's mouths. The exception is breastfeeding, where it can pass back and forth between mother and baby, so both need treating at the same time.
How quickly does Daktarin work?
Most people notice an improvement within one to two days, but the full seven-day course is important to prevent it coming back. Don't stop early even if you feel better.
Can stress cause oral thrush?
Indirectly, yes. Prolonged stress suppresses the immune system, which is what normally keeps Candida in check. If you notice thrush cropping up during stressful periods, it could be related.
Treat oral thrush with Pharmica
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This article is intended for informational purposes only and does not replace professional medical advice. Always read the patient information leaflet supplied with your medication and speak to a healthcare professional if you have specific concerns.