Oral cancer refers to cancers that occur in the lips, tongue, floor of the mouth, palate, gums, cheeks, alveolar mucosa and salivary glands, and is more prevalent in adults and more common in men. Smoking, alcohol consumption, viral infection, dietary habits, poor nutrition and local irritation may all cause oral cancer. Experts remind that oral cancer needs early detection, early diagnosis and early treatment. The incidence of oral cancer can be increased by more than 75% due to the synergistic effect of drinking and smoking, or drinking alcohol and not paying attention to oral hygiene. Smoking can induce precancerous lesions such as oral mucosal leukoplakia, while drinking alcohol can cause mucosal burns and increase the absorption of carcinogenic substances, increasing the risk of tongue and floor of mouth cancers. Poor oral hygiene or chronic inflammatory ulcers, or traumatic ulcers in the oral cavity, and long-term oral ulcers that do not heal should be noted, especially tongue cancer is the most common. Warning signs and symptoms of oral cancer are as follows: 1. white, red and dark spots on the oral mucosa; 2. abnormal swelling and enlarged lymph nodes in the mouth and neck; 3. repeated unexplained bleeding in the mouth; 4. unexplained numbness and pain in the mouth, face, pharynx and neck. Patients with the above symptoms or signs should be alerted for timely diagnosis and early treatment.