What is the difference between a hematoma and a seroma?
Both are fluid collecting around an implant, but a hematoma is blood — usually early, tense, and bruised — while a seroma is clear serum that tends to build more slowly and quietly.
Swelling after breast implant surgery has two classic fluid culprits, and telling them apart matters because the timelines and treatments differ. The distinction starts with what is in the pocket: blood in a hematoma, protein-rich serum in a seroma.
Timing, feel, and treatment diverge
A hematoma usually declares itself within the first days after surgery: one breast becomes tight, swollen, more painful, and often discolored as a vessel keeps oozing into the pocket. Sizable ones are typically evacuated surgically, both for comfort and because retained blood is linked to later capsule problems. A seroma is slower and softer — a gradual swelling, often without pain, that may be observed, aspirated with a needle, or drained depending on size and timing.
How each is handled varies with the amount of fluid, when it appeared, and individual healing, so the same swelling can be managed differently in two patients. New or growing swelling after implant surgery — early or late — is a reason to consult your surgeon or a breast specialist rather than to wait it out.
MediIndex articles are for general information only and are not medical advice, diagnosis, or advertising. Outcomes vary by individual — consult a board-certified specialist for personal decisions.