A positive IgG antibody to herpes simplex virus type 1 often indicates that the patient has a history of previous herpes simplex virus type 1 infection or that the infection is in the recovery phase. Because herpes simplex virus infection stimulates the body’s immune response, IgM antibodies are produced first and then IgG antibodies are produced. IgG antibodies are relatively small in molecular weight, appear 7-10 days after infection, easily cross the blood-brain and placental barriers, and remain in the bloodstream for long periods of time, some up to several years. When IgG antibodies appear in the patient’s test, it may be due to the fact that the antibody concentration has not completely disappeared and is influenced by certain time factors. If IgM antibodies are also positive at this time, then herpes simplex virus infection is considered. Herpes simplex virus infection often occurs when the body is weak, such as fever, menstruation, pregnancy, gastrointestinal disorders and emotional changes. type 1 infection mainly occurs in the head, face and upper body skin, causing herpes simplex keratitis, oral herpes, skin herpes, etc., of which herpes simplex encephalitis is an important life-threatening factor. Through early consultation, active antiviral treatment, immunotherapy and strengthening of the body, the prognosis is generally better.