How did a black bubble grow in oral cavity to return a responsibility

A black blister in the mouth is mostly caused by careless biting. Bite and scald can also cause black blisters in the mouth when eating. Most of the blisters do not need to be treated. Under normal circumstances, they will be absorbed by themselves. It can also be used to make the affected part heal quickly. After the incision, it is also necessary to spray drugs to promote wound healing. At the same time, oral antibiotics are needed to prevent infection. And before the wound has not completely healed, it is not allowed to eat spicy food.