There are several possible causes for blisters inside the lips: 1. traumatic blood blisters, inadvertent bites by sharp teeth, or eating harder, hotter food, choking injuries produce blood blisters, which can then be cut open, discharging pus and blood, and apply drugs that promote healing, such as recombinant human epidermal growth factor gel or topical solutions. 2. blisters inside the lips, possibly due to long-term bad habits of lip biting The mucus gland cysts, generally there are mucus gland glands in the lips, and in the process of biting the lips for a long time, it may cause the blockage of the gland ducts, there will be mucus gland cysts, so then you need to remove the cysts to restore health. 3, blistering inside the lips, may also be caused by the herpes virus, such as herpes simplex virus infection, it is easy to appear the phenomenon of blistering inside the lips, generally The actual fact is that you can use antiviral medication to help you get the most out of your life. You can choose to use antiviral medications, such as ribavirin, or choose acyclovir ointment for topical application, and it is also recommended to improve body resistance, you can use appropriate drugs to improve resistance, such as transfer factor.