Seroma
A fluid pocket that can form after surgery or injury
Quick Facts
- Type: Post-surgical / post-injury complication
- What it is: A buildup of clear body fluid
- Common after: Surgery, especially with tissue removal
- Outlook: Often resolves on its own
Overview
A seroma is a collection of clear, straw-colored fluid that builds up in a space under the skin, most often after surgery or a significant injury. The fluid, called serous fluid, leaks from small blood vessels and tissues as the body responds to the disturbance, and it pools in the space left where tissue was removed or separated.
Seromas are common and usually not dangerous. Many are reabsorbed by the body over a few weeks. Larger ones may need to be drained, and any seroma can occasionally become infected, so it is worth monitoring.
Symptoms
- A soft, swollen lump under the skin, often near a surgical incision
- A sense of fullness, tightness, or pressure in the area
- Fluid that may shift or feel like it moves when pressed
- Mild tenderness, though seromas are often not very painful
- Occasionally, clear fluid leaking from the incision
Increasing redness, warmth, pain, pus, or fever may indicate infection and should be checked promptly.
Causes
Seromas form when fluid accumulates faster than the body can clear it from a space created during surgery or injury. Contributing factors include:
- Surgery with tissue removal: Procedures such as breast surgery, hernia repair, and abdominal operations leave spaces where fluid can collect.
- Disruption of lymph vessels: Cut or damaged lymph channels leak fluid.
- Injury: A blunt blow that separates layers of tissue.
- Large surgical wounds and early movement that keep the tissue layers from sealing together.
Risk Factors
- Extensive surgery or removal of a large amount of tissue
- Operations involving lymph nodes
- Larger body size or more body fat in the surgical area
- Not using a compression dressing or drain when advised
- Strenuous activity too soon after surgery
Diagnosis
A doctor can often recognize a seroma from a soft, fluid-filled swelling near a recent incision. When the diagnosis is unclear or the collection is deep, an ultrasound can confirm that the lump is fluid rather than solid tissue or a blood collection. If infection is suspected, a sample of the fluid may be tested.
Treatment
Treatment depends on the size and symptoms:
- Observation: Small seromas often need no treatment and are reabsorbed over a few weeks.
- Compression: A snug dressing or garment can help reduce fluid buildup.
- Drainage: Larger or uncomfortable seromas may be drained with a needle, sometimes more than once.
- Surgical drains: A temporary drain may be placed during or after surgery to prevent fluid from collecting.
- Treating infection: Antibiotics and drainage if the collection becomes infected.
Prevention
- Follow your surgeon's instructions on activity limits after surgery
- Wear compression garments or dressings if recommended
- Keep any surgical drains clean and in place as directed
- Avoid strenuous lifting and movement of the area during early healing
When to See a Doctor
Contact your doctor if a swelling near a surgical or injury site grows, becomes uncomfortable, or leaks fluid. Seek prompt care if the area becomes increasingly red, warm, or painful, drains pus, or if you develop a fever, since these can signal an infection that needs treatment.
Frequently Asked Questions
Is a seroma dangerous?
Most seromas are not dangerous and resolve on their own over a few weeks. The main concerns are discomfort, delayed healing, and the small chance of infection, so a growing or painful seroma should be checked by a doctor.
What is the difference between a seroma and a hematoma?
A seroma is a pocket of clear serous fluid, while a hematoma is a collection of blood. Both can cause swelling after surgery or injury, and an ultrasound can help tell them apart when needed.
Will a seroma go away on its own?
Many small seromas are gradually reabsorbed by the body without any treatment. Larger or uncomfortable ones may need to be drained with a needle, sometimes more than once, and compression can help reduce fluid buildup.
How do I know if my seroma is infected?
Signs of infection include increasing redness, warmth, pain, pus or foul-smelling drainage, and fever. If you notice these, contact your doctor promptly, as an infected fluid collection usually needs drainage and antibiotics.
References
- MedlinePlus, U.S. National Library of Medicine. Surgical wound care.
- American Cancer Society. Seroma after breast surgery.
- StatPearls, National Library of Medicine. Seroma.