The lesions, which may have a cottage cheese-like appearance, may be painful and may bleed slightly when you scrape them or brush your teeth. In severe cases, these lesions can spread into your esophagus, or swallowing tube which would cause:

• Pain or difficulty swallowing
• A feeling that food gets stuck in your throat
• Fever, if the infection spreads beyond the esophagus

Thrush can spread to other parts of the body, including the lungs, liver, and skin. This happens more often in people with cancer, HIV, or other conditions that weaken the immune system.

How Is Thrush Diagnosed?
Your dentist can diagnose thrush by examining your mouth. He or she looks for the distinctive white lesions on your mouth, tongue, or cheeks. Lightly brushing the lesions away reveals a reddened, tender area that may bleed slightly. A microscopic examination of tissue from a lesion can confirm the diagnosis.

Thrush that extends into your esophagus may require other tests to make the diagnosis. Such tests might include:

• Taking a throat culture by swabbing the back of your throat with sterile cotton and studying the microorganisms under a microscope
• Performing an endoscopy of your esophagus, stomach, and small intestine — examining the lining of these body areas with a lighted camera mounted on the tip of a tube passed through these areas)
• Taking X-rays of your esophagus