Oral thrush: causes, signs and treatment

Creamy white patches on the tongue or inner cheeks, a cottony feeling, and a sore mouth are the hallmarks of oral thrush, a fungal infection that is more common than many people realise. It is usually easy to treat, but it often shows up because something else, from a dry mouth to a course of antibiotics, has tipped the balance. Here is what thrush is, why it appears, and when to get it looked at.

What does oral thrush look like?

The classic sign is creamy white or cream-coloured patches, a little like cottage cheese, on the tongue, inner cheeks, roof of the mouth or throat. Wiping them away tends to leave a red, tender spot that may bleed slightly. Some people also notice a loss of taste, a cottony feeling, soreness, or cracking at the corners of the mouth. In babies it can appear as white patches that do not rub off like milk does.

Why it happens

Candida lives harmlessly in most mouths, kept in check by the body and by saliva. Thrush appears when something lets it overgrow: a dry mouth, a recent course of antibiotics, inhaled steroids for asthma, diabetes that is not well controlled, dentures that do not fit well or are not cleaned, smoking, or a weakened immune system. Age matters too, it is more common in babies and in older adults. Because it so often reflects a trigger, finding that trigger is part of the fix.

How it is treated

Most thrush clears with antifungal medicine, commonly a gel or liquid used in the mouth, together with sorting out whatever set it off, cleaning and removing dentures overnight, rinsing the mouth after a steroid inhaler, or improving blood-sugar control. The exact medicine and length of treatment depend on the cause and your general health, which is why it is something to have assessed rather than self-treated with an over-the-counter guess. Keeping the mouth clean and moist supports recovery.

When to get it checked

See a dentist or doctor if white patches last more than a week or two, keep coming back, make eating or swallowing painful, or appear while you are unwell. Thrush that keeps returning can be a clue to an underlying trigger worth identifying. And any red or white patch in the mouth that does not wipe away, or does not heal, should be checked to rule out other causes, our guide to early signs of oral cancer explains why persistent patches deserve a look. At our clinic in Viman Nagar, Pune, this is part of routine general dentistry care.

Sources & further reading

NHS, Dental Health · American Dental Association (MouthHealthy) · World Health Organization, Oral Health · Indian Dental Association