Patient education: Seroma (The Basics)

What is a seroma? — A seroma is a build-up of fluid called "serum" in part of the body. (Serum is the liquid part of blood.) It can happen between 2 layers of tissue, either under your skin or in a space inside your body.

Seromas usually form after a surgery. They are most common after major surgeries, or ones where a lot of tissue is removed. But they can sometimes form after minor surgery, too.

Some types of surgery that can cause seromas to form include:

●Hernia repair

●Breast surgery (including surgery to remove part or all of a breast for cancer treatment, breast reconstruction, or breast enlargement)

●Thyroidectomy (surgery to remove part or all of the thyroid gland)

●Lymphadenectomy (surgery to remove a lymph node)

Seromas take some time to form. When a seroma happens, it usually takes a week or 2 after the surgery to become noticeable.

Sometimes, a seroma can also form after a serious injury, such as a fall or "crush injury."

What are the symptoms of a seroma? — Seromas do not always cause symptoms. But when they do, symptoms can include:

●Swelling

●Pain or discomfort

●Drainage of clear or slightly red fluid

Sometimes, a seroma can get infected. If your seroma is infected, you might also have:

●A fever

●Redness of your skin in that area

●Hardened skin in that area

●Pus draining from the area

Should I see a doctor or nurse? — Yes. If you recently had surgery and you notice a lump or swelling in the area, tell your doctor or nurse.

Will I need tests? — Maybe. Usually, doctors can tell if you have a seroma by doing an exam. In some cases, doctors might do imaging tests, such as an ultrasound or CT scan to confirm if your problem is a seroma or something else. Imaging tests create pictures of the inside of your body.

If your doctor thinks your seroma might be infected, they might want to collect some of the fluid from the area and examine it. A sample of the fluid might also be tested in a lab.

How are seromas treated? — How your seroma is treated depends on its size and your other symptoms:

●If your seroma is small and you have no symptoms, your doctor will probably just watch it and wait for it to go away on its own

●If your seroma is large or causing symptoms, your doctor might drain some of the fluid out with a needle. They might need to do this a few different times, or put a temporary draining tube in the seroma. Rarely, you might need another surgical procedure to remove your seroma if it keeps coming back.

If your seroma is infected, your doctor will drain it, no matter what size it is. To do this, they will reopen part or all of your incision and clean the area. Sometimes this needs to be done in the operating room. You will need to take antibiotics to treat the infection.

Can seromas be prevented? — Ways of preventing seromas might include:

●Drains, for some types of surgery – These are small tubes that let fluid flow out of your body and into a small container. Drains are usually removed when they are draining less than 1 fluid ounce per day. But even with drains, seromas can sometimes form.

●Using a compressive dressing – This is a type of bandage your doctor puts on at the end of your surgery. It puts pressure on the area where you had surgery, and can lower the chance that a seroma will form. If a seroma does form, the dressing might keep it from getting very big. Be sure to follow your doctor's instructions about when to remove this dressing.

●Icing your incision – You can use ice for the first 2 to 3 days after the surgery, when swelling is most likely to happen. Put a cold gel pack, bag of ice, or bag of frozen vegetables on the injured area every 1 to 2 hours, for 15 minutes each time. Put a thin towel between the ice (or other cold object) and your skin.

●Limiting some types of movement while you are healing – Some types of movement can increase the chances of a seroma forming. For example, after a mastectomy (surgery to remove a breast), it's OK to use your arms to do normal tasks, like brushing your teeth or hair. But doing heavy exercises, like push-ups or lifting weights, can make a seroma more likely to form in the place where tissue was removed. It's best to wait until you are completely healed before going back to these activities. Ask your doctor what is right for you and the type of surgery you had.

More on this topic

Patient education: Groin hernias (The Basics)
Patient education: Abdominal wall hernias (The Basics)
Patient education: Choosing surgical treatment for early-stage breast cancer (The Basics)
Patient education: Breast reconstruction after mastectomy for cancer (The Basics)
Patient education: Thyroid cancer (The Basics)
Patient education: Thyroid nodules (The Basics)
Patient education: Thyroidectomy (The Basics)
Patient education: Port removal (The Basics)

Patient education: Lymphedema after cancer surgery (Beyond the Basics)
Patient education: Surgical procedures for breast cancer — Mastectomy and breast-conserving therapy (Beyond the Basics)
Patient education: Thyroid nodules (Beyond the Basics)