A seroma is a collection of fluid that builds up under the surface of your skin. Seromas may develop after a surgical procedure, most often at the site of the surgical incision or where the tissue was removed. The fluid, called serum, doesn’t always build up right away. The swelling and fluid may start collecting several weeks after surgery.

A seroma is a buildup of fluid called serum that collects beneath the skin after surgery. Typically located near the incision site or where tissue was removed, seromas can often be easily managed by your cosmetic surgeon or may resolve on their own; it is one of the most common postoperative complications.