Red, hairy, bumpy: 10 clues your tongue can tell you about your health

2. White patches

This means you could be having a yeast infection or thrush. When you take antibiotic medicine, it can allow yeast to grow. In other cases, thrush can also develop in people with autoimmune diseases and diabetes and those undergoing chemotherapy. If you think you might have thrush, doctors suggest you should have it checked.