There are more reasons for labia majora edema, which are considered to be related to friction, gynecological inflammation, trauma and other factors. 1. Friction: for obese women, labia majora are easily rubbed against underwear or bilateral thighs, and friction can easily lead to local tissue congestion and edema. 2. Gynecological inflammation: If women have vaginitis, pelvic inflammatory disease and other gynecological inflammation, due to the stimulation of inflammatory exudate and may cause labia majora congestion and edema or pain. 3. Trauma: Because the labia majora tissue is relatively loose, local external forces can easily lead to vascular or tissue fluid exudation, which can easily form edema or hematoma. Labia majora edema may also have other causes, it is recommended to go to the regular hospital in time to improve the relevant examination, clear cause of the disease under the guidance of doctors and active treatment.