The inside of the mouth is normally lined with a special type of skin (mucosa) that is smooth and coral pink in color. Any alteration in this appearance could be a warning sign for a pathological process. The most serious of these is oral cancer. The following can be signs at the beginning of a pathologic process or cancerous growth:

- Reddish patches (erythroplasia) or whitish patches (leukoplakia) in the mouth
- A sore that fails to heal and bleeds easily
- A lump or thickening on the skin lining the inside of the mouth
- Chronic sore throat or hoarseness
- Difficulty in chewing or swallowing

These changes can be detected on the lips, cheeks, palate and gum tissue around the teeth, tongue, face and/or neck. Pain does not always occur with pathology, and curiously, is not often associated with oral cancer. However, any patient with facial and/or oral pain without an obvious cause or reason may also be at risk for oral cancer.