Herpes on the mouth, also known as oral and labial herpes, is caused by herpes simplex virus type 1 infection. Oral and labial herpes is a skin herpes caused by herpes simplex virus type 1 infection, which manifests itself in the form of small, dense blisters that appear rapidly on the lips and mouth and are more painful. Oral and lip herpes often recurs. After infection with the virus, herpes recurrence is easily caused if the patient develops fever, cold and exertion. Patients with impaired immune function, such as patients infected with human immunodeficiency virus, patients with malignant tumors, patients after organ transplantation, and women during menstruation are prone to herpes orofacialis. If the patient only has herpes on the lips and mouth, it may heal in 1-2 weeks without treatment, and may improve more quickly with the use of antiviral drugs as prescribed by the doctor. There is no vaccine to prevent herpes orofacialis, and avoiding close contact with people with herpes orofacialis is an effective preventive measure.