Blood blisters in the mouth may have the following causes: 1, may be due to eating harder food or larger pieces of food resulting in choking injury, this choking injury can easily cause blood blisters in the mouth, you can go to the stomatology department to make an incision to exclude the pus and blood, after removing the blood can also choose to remove the vesicle wall, and then apply drugs to promote healing, so as to promote its rapid anti-inflammatory, pain relief, commonly used drugs such as compound cortical dispersion, tin class dispersion or bead yellow dispersion, etc.; 2, may be hemangioma, which is usually caused by vascular malformation, can be local injection to promote the receding of its blood blisters, can also choose to surgical removal treatment.