If a woman has a relatively large pack on her vulva, it is basically on the left or right side of the posterior union. The most common cause is a vestibular gland cyst. If there is frequent inflammation of the vulva or inflammation of the vagina, this causes an obstruction of the vestibular gland ducts, which leads to the formation of a relatively large localized cyst as a result of the accumulation of fluid. If there is no inflammation, these cysts do not cause pain. However, once there is an inflammatory reaction, there will be more severe pain, and in severe cases, this may lead to localized suppuration, requiring incision and drainage. In the case of vestibular gland cysts, if they are relatively small, they can be left untreated. For large cysts, it is best to incise and drain them to achieve a complete cure.