Herpes is a viral skin disease that can cause changes in the skin and mucous membranes. Acyclovir is an antiviral drug that can be used to treat herpes simplex virus infection. The course of treatment with acyclovir for herpes is usually 5-7 days, but the specifics need to vary from person to person and generally should not exceed 14 days. Because acyclovir is mainly metabolized by the kidneys, if taken for a long time it may increase the burden on the kidneys and lead to abnormal kidney function or induce kidney stones, etc. Herpes has the possibility of self-healing, and if it is treated with acyclovir, it usually works in 3-5 days, and the symptoms basically disappear after another week or so of use. If the symptoms still do not improve at this time, it is recommended to seek medical advice for clarification of viral culture and pathological examination, and there may be drug resistance problems. Treatment can be switched to other drugs, such as sodium phosphonate or valacyclovir, under the guidance of a doctor. It is recommended to ensure adequate water intake while applying acyclovir to prevent drug deposition. It is important to observe the condition. If symptoms such as oliguria, anuria, nausea, vomiting and back pain occur, the medication should be stopped and medical examination should be sought. Patients with herpes should pay attention to skin cleanliness, avoid scratching the affected area, should maintain a light diet, and disinfect clothing well to prevent infection to others.