Thrush mouth, also known as oral thrush or oral candidiasis, is a fungal infection of the mouth caused by the overgrowth of Candida albicans, a type of yeast. It can cause creamy white, slightly raised, sore patches in the mouth or on the tongue, which can make eating and drinking difficult. Other symptoms of thrush mouth include redness, irritation, and pain under dentures, a cottony feeling in the mouth, and loss of taste. Thrush mouth is not contagious, but it can be transmitted through other means, such as breastfeeding. Thrush mouth can affect anyone, but it is more likely to occur in babies, older adults, and people with weakened immune systems or certain health conditions. Thrush mouth is usually treated with antifungal medication, and if left untreated, it can spread further into the body, which can be serious. If you suspect that you have thrush mouth, it is important to see a healthcare provider for diagnosis and treatment.