Vulvar swelling after coitus may be due to improper sex, gynecological inflammation, allergic reaction and other reasons, need to be specifically analyzed. 1. Improper sex life: excessive mechanical stimulation during coitus can cause vulvar injury, swelling and pain, don’t worry too much, it can recover by itself. 2. Gynecological inflammation: when a woman suffers from vaginitis and vulvitis, mechanical stimulation exacerbates the inflammatory reaction and increases local edema, which can lead to further damage to the vaginal mucosa, resulting in edema of the vagina and vulva. 3. Allergic reaction. The condom or diaphragm used during intercourse, as well as male semen, are allergens that trigger allergic reactions in some women. When the vulva is swollen and painful after intercourse, if the symptoms continue to be unrelieved, it is recommended to go to the hospital in time and take standardized treatment under the guidance of the doctor to promote the alleviation of the condition.