What are the signs and symptoms of mouth cancer?

Anything abnormal: First you look for something abnormal: pain, swelling, discoloration from normal, etc. These generally lead to a determination of the cause. If the cause is not solved with a dental procedure (root canal, extraction, etc) then the cause is abnormal. A biopsy or blood test is often recommended and/or referral to an oral surgeon. If you have habits like drinking, smoking, tobacco, go see a dentist!

Most common: Most commonly, an ulcer that does not heal. Other symptoms include a lump in the mouth, unexplained bleeding or pain in the mouth. See oral surgeon or ENT doc for exam if you are worried.