There are many early symptoms of oral cancer, including ulcers that have not healed for more than three weeks or painful swellings. Oral cancer is a disease of oral cavity, commonly known as oral ulcers. A normal ulcer can heal itself in two weeks, but if it does not heal in more than two weeks, or if it recurs, you need to be alert to the possibility of oral cancer. If the ulcer does not heal in more than two weeks, or if it recurs, you should be alerted to the possibility of oral cancer. Unexplained bleeding of gums, or cauliflower-like growth of gum tissue, bleeding and ulceration, etc. White spots, red spots, etc. appear in the oral cavity, or the oral cavity becomes numb for unknown reasons, dry and burning, etc. The oral mucosa may have white or brownish changes, and the mucosa may become rough or thickened with hard nodules. Or the mucosa may have ulcerative changes, with elevation on all sides and depression in the center, covered with necrotic material on the surface, and pain is more intense, which are all early signs of oral cancer. If oral cancer invades the nerve, there will be a certain degree of mouth opening restriction, inability to eat or difficulty in eating. Therefore, there are still many symptoms in the early stage of oral cancer, mainly including persistent oral ulcers and swollen plaques in the mouth, etc. If these conditions appear, they should be detected and treated early.