Labia are part of external female genital anatomy (vulva) & consist of labia majora (hair bearing, fulller, outer) serving from the embryonic genital swellings/folds whereas labia minora from from urethral folds. Swelling of either may be due to congenital deformities or acquired tumors of the tissues (skin, fat, vessels) or a hernia, or allergic reaction or trauma or infection & many other causes.
