My left lower outside vaginal lip is swollen and has been that way for about two months. sex has not been a contributing factor. it does not hurt.

Bartholins Cyst: The most common cause for a painless swelling in the lower aspect of the outer labia on one side is a Bartholin's Cyst. The Bartholin's glands secrete fluid thru the Bartholin's Duct that helps lubricate the vagina during intercourse. The duct can become blocked leading to a soft painless swelling in the location you describe. A much less likely cause is a hernia. SEE: http://bit.ly/1vBT7T3