Initially, one may not even notice symptoms of oral thrush. Depending on the underlying cause, signs and symptoms may develop suddenly and persist for a long time. They can include:

• Creamy white lesions on the tongue, inner cheeks and sometimes on the roof of the mouth, gums and tonsil
• Lesions with a cottage cheese-like appearance
• Pain
• Slight bleeding if the lesions are rubbed or scraped
• Cracking and redness at the corners of your mouth
• A cottony feeling in the mouth
• Loss of taste
• In severe cases, the lesions may spread downward into the esophagus. If this occurs, one can experience difficulty swallowing or feel as if food is getting stuck in the throat

Oral thrush and other Candida infections can occur when your immune system is weakened by disease or drugs such as prednisone or inhaled steroids or when antibiotics disturb the natural balance of microorganisms in your body.

Normally your immune system works to repel harmful invading organisms, such as viruses, bacteria and fungi, while maintaining a balance between “good” and “bad” microbes that normally inhabit your body. But sometimes these protective mechanisms fail, which can allow an oral thrush infection to take hold.