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What Is a Seroma After Surgery?

A seroma is clear fluid that collects under the skin after surgery, often 7 to 10 days later. Small ones usually settle; larger ones may need needle drainage.

By Vireon Medical Editorial TeamFirst published Evidence checked through

Short answer

A seroma is a pocket of clear, pale-yellow fluid that collects under the skin in the space left by surgery. It is common after operations that lift large areas of skin, such as tummy tucks and breast surgery, and usually appears 7 to 10 days afterwards. Small seromas often go away on their own within weeks, while larger or recurring ones may need draining with a needle. Whether treatment is needed depends mainly on size, symptoms and any signs of infection.

Key points

  • Seroma fluid comes from blood plasma and lymph, not pus.
  • Breast surgery, hernia repair and plastic surgery are common causes.
  • Small seromas may settle in about a week; larger ones can take up to six weeks.
  • Treatment ranges from watching it, to needle drainage, to a temporary drain.
  • New swelling around a breast implant more than a year after surgery needs separate assessment.

Why a seroma forms

When surgery separates skin and fat from the tissue underneath, it leaves a potential space. Serous fluid, a clear liquid made from blood plasma and lymphatic fluid, can collect there.1 Cleveland Clinic lists breast surgery, hernia repair, plastic surgery and spinal fusion as the most frequent causes.1

Some people are more likely to develop one. Recognised risk factors include age over 65, larger or more extensive operations, previous chemotherapy, too much movement of the area during healing, and overweight or obesity.1 After a tummy tuck, the NHS lists a collection of fluid in the operated area among the possible complications.2

What it looks and feels like

Symptoms usually appear 7 to 10 days after surgery. Typical signs are a soft, fluid-filled swelling, pain or soreness, reduced movement in the area and a pulling feeling on the stitches; some people notice nothing at all.1

It is different from a haematoma, which is a collection of blood, and from an abscess, which is infected fluid (pus). A seroma can become infected, though, so changes in the swelling matter.1

How seromas are treated

ApproachWhen it may be used
Watching and waitingSmall seromas that cause no pain, which often resolve as the body reabsorbs the fluid
Needle aspirationLarger or uncomfortable seromas; may need repeating because fluid can return
Temporary drainA seroma that keeps coming back; a small tube is left in for a few days
Sclerosing agentMedicine placed in the pocket to help its walls stick together
SurgeryThe last option, to remove the lining of a persistent seroma
Treatment options for seroma, from least to most invasive. Source: Cleveland Clinic.1

Small seromas may shrink in a little over a week, while larger ones may take up to six weeks to settle.1 A seroma left for a long time can develop a thick wall (sometimes called a pseudocyst or chronic seroma), which may need surgical removal.1

Possible complications

Most seromas are a nuisance rather than a danger. Cleveland Clinic describes the less common problems: infection turning the fluid into an abscess, with redness, warmth, pain and fever; a large seroma pressing on the wound until it reopens (wound dehiscence); and, in operations involving a tissue flap, reduced blood flow causing part of the flap to die (necrosis).1

Can seromas be prevented?

Surgeons use several techniques to reduce the space where fluid can gather. In tummy tucks, progressive tension sutures (stitches that fix the skin flap to the muscle layer underneath at intervals) have been studied most. A 2017 meta-analysis found that adding these sutures to drains lowered the seroma rate compared with drains alone.3 A 2024 meta-analysis of 24 studies and 750 patients found fewer seromas with these sutures than with drains, but only 2 of the studies were randomised trials.4 The evidence for this technique is Moderate.

Compression garments are often assumed to prevent seroma, but a 2023 review across plastic surgery found no effect on seroma rates.5 The evidence that garments prevent seroma is Insufficient. Following advice on rest and limiting movement in the early days is sensible, since excess movement is a recognised risk factor.1

A special case: late fluid around breast implants

Timing matters with breast implants. The Medicines and Healthcare products Regulatory Agency (MHRA) notes that the most common sign of breast implant-associated anaplastic large cell lymphoma (BIA-ALCL, a rare lymphoma) is a late seroma, and advises anyone with a seroma, lump or swelling more than a year after implantation to see their implanting surgeon or GP.6

When to seek medical advice

Contact your surgical team if a seroma is uncomfortable, getting bigger, not improving after several weeks, or shows signs of infection such as redness, warmth, increasing pain or fever. Call your surgeon straight away if the fluid looks like pus.1 New swelling around a breast implant more than a year after surgery should also be assessed.6

Common questions

Is a seroma dangerous?

Usually not; most are small and settle, but infection, wound reopening or a persistent walled-off seroma can occur.1

Should I try to drain it myself?

No. Drainage is done by a clinician with a sterile needle or drain, because a seroma can collect bacteria and become an abscess.1

Will it come back after draining?

It can, which is why aspiration sometimes has to be repeated or a temporary drain placed.1

Does a seroma affect the final result?

It can if it persists: a long-standing seroma can form a thick-walled pocket that may need surgery, and a large one can reopen the wound.1

Bottom line

A seroma is a common, usually harmless fluid collection after surgery that often resolves by itself or with simple drainage. Signs of infection, a growing swelling or late fluid around a breast implant are the situations that need prompt review.

Sources

  1. Cleveland Clinic. Seroma. Cleveland Clinic. https://my.clevelandclinic.org/health/diseases/seroma. Accessed 5 November 2026.
  2. NHS. Tummy tuck (abdominoplasty). NHS website. https://www.nhs.uk/conditions/cosmetic-procedures/tummy-tuck/. Accessed 5 November 2026.
  3. Jabbour S, Awaida C, Mhawej R, Habre SB, Nasr M. Does the addition of progressive tension sutures to drains reduce seroma incidence after abdominoplasty? A systematic review and meta-analysis. Aesthetic Surgery Journal; 2017;37(4):440–447. doi:10.1093/asj/sjw130. https://academic.oup.com/asj/article/37/4/440/2354563
  4. Rao G, Daneshi K, Ceccaroni A, et al. A systematic review and meta-analysis evaluating the surgical outcomes of progressive tension suturing compared to drains in abdominoplasty surgery. Aesthetic Surgery Journal; 2024. PMID: 39078654. https://pesquisa.bvsalud.org/brasil/resource/pt/mdl-39078654
  5. Ormseth BH, Livermore NR, Schoenbrunner AR, Janis JE. The use of postoperative compression garments in plastic surgery: necessary or not? A practical review. Plastic and Reconstructive Surgery Global Open; 2023;11(9):e5293. doi:10.1097/GOX.0000000000005293. https://doaj.org/article/d7d05b1777874bf3be6a07bc9b617da6
  6. Medicines and Healthcare products Regulatory Agency. Breast implant associated anaplastic large cell lymphoma (BIA-ALCL). GOV.UK; updated 2025. https://www.gov.uk/guidance/breast-implants-and-anaplastic-large-cell-lymphoma-alcl. Accessed 5 November 2026.

Article history

  • — First published.