Suddenly black blood blisters in the mouth are generally caused by occlusal trauma or oral mucosa mucous membrane pemphigoid .
1. Occlusal trauma: when eating accidentally, teeth bite into the buccal mucosa, or food stimulation of the palate, dentures cover too small and other reasons for bite wounds, the emergence of submucosal capillary hemorrhage and rupture, in the corresponding part of the emergence of black blood blisters, small blisters do not need to be dealt with, to be naturally absorbed can be, large blisters affecting the eating, you can use a sterilized needle to puncture.
2. oral mucosal pemphigus: an autoimmune disease, with different types, in the oral mucosal manifestations can also appear transparent blisters or turbid blisters, blister wall relaxation, easy to rupture, systemic symptoms are not obvious, can use glucocorticoids for treatment.
There are other reasons for the appearance of black blood blisters in the oral cavity, it is necessary to consult a doctor in time, under the guidance of the doctor for examination and treatment.