The swelling and pain on one side of the vulva may be caused by inflammation of the vestibular gland cysts. Women have vestibular glands on the left and right side of the inner labia majora, and if vaginal inflammation or increased secretions cause the opening of the vestibular gland to become blocked, vestibular gland cysts will form. The vestibular gland cyst or vestibular gland abscess. If it is a vestibular gland abscess, you need to make an incision and drainage. After the operation, you should give oral anti-inflammatory and hemostatic drugs, pay attention to keeping the vulva clean and hygienic, and have regular reviews. If it is a vestibular gland cyst, you can give a 1:5000 potassium permanganate bath and give anti-inflammatory drugs orally for conservative treatment.