Chewing betel nut may cause oral cancer. 1. Betel nut is relatively hard, when chewing betel nut, it is easy to cause mechanical trauma to the oral mucosa. Occasionally eating betel nut once or twice is not a big problem, but eating betel nut for a long time will make the trauma to the oral mucosa recurring, which will cause oral submucosal fibrosis, which is a kind of pre-cancerous lesion, and if the condition further develops, oral cancer may occur. 2. Nowadays, betel nut is usually processed, and some tobacco ingredients will be mixed in the process, which will greatly increase the chance of oral cancer. After chewing betel nut, the chemical components in betel nut will synthesize nitroso, which is a very strong carcinogen, so regular consumption of betel nut may lead to oral cancer. If you have the habit of chewing betel nut, it is recommended to change it in time.