Blisters on the mouth with cold are considered to be caused by low resistance of the body, which leads to herpes simplex virus infection in the body, and can be treated with supportive therapy and medication. Blisters on the mouth are mostly related to herpes simplex virus infection, mainly manifested as a cluster of small blisters around the mouth, accompanied by a slight pain or burning sensation. The disease is self-limiting and usually improves in 7-10 days. During the onset of the disease, it is important to drink plenty of fluids, get enough sleep, and refrain from scratching with your hands as supportive treatment. Acyclovir cream can also be applied topically. If there is a secondary bacterial infection, such as a pustule, mupirocin ointment can be applied topically. Blisters on the mouth can also be caused by other diseases, if the symptoms are not relieved or aggravated, it is recommended to consult a doctor to clarify the cause of the disease and follow the doctor’s instructions for treatment.