Pus in a Wound After Surgery

What Exactly Is Pus?

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Pus is also known as purulent drainage. It is a general term for the thick, often white fluid that collects at the source of an infection. Pus can occur around many types of infections, but it can be especially concerning after surgery. 

Drainage that appears in an incision may be a sign of infection, but not all drainage is pus. Still, it can be an alarming thing to see at your surgical incision.

This article discusses pus in surgical incisions. It also looks at the ways post-surgical infection is treated.

Abdominal surgery incision
Barrett Forster / Getty Images

Pus Explained

Pus is made from:

  • Dead tissue
  • White blood cells
  • Damaged cells

When your body fights an infection, it sends white blood cells to the source. The white blood cells help stop the germs from infecting more tissue. Pus is a byproduct of this process.

When you see pus, it means your body is working to fight an infection. Still, it's never a good thing when a wound becomes infected.

Pus is usually white or a yellow-white color. Sometimes it can be greenish, blood-tinged, blue, or in rare cases even brown. It can also have a foul odor. 

Pus appears in a surgical incision when it is becoming infected. It's a sign that you need further treatment. Surgical infections can become serious quickly, so if you see pus call your surgeon at once.

An infection that spreads and reaches the bloodstream is called sepsis. Sepsis can become life-threatening.

Drainage From a Surgical Incision

Keep in mind that there are many types of drainage, ranging from normal to serious.

It is possible to have drainage that looks like pus but is actually just normal drainage. The only way to tell the difference is to seek medical attention. This is especially important if the drainage is from a surgical wound. 

If drainage from your surgical wound smells bad, tell your surgeon right away.


Not all drainage is pus. To be sure, see your surgeon right away.

Abscesses Explained

Some infections only produce a small amount of pus. In others, there may be significant buildup. Large amounts of pus may not always be visible because they are under the skin or deep inside an incision.

An abscess happens when drainage does not leak out. Abscesses can appear almost anywhere in the human body. Acne whiteheads are examples of very small abscesses.

Pus can be found in large amounts when an abscess is severe or goes untreated. This type of abscess can start with something as simple as an infected tooth, an infected surgical incision, or even a boil on the skin.


An abscess is an infection that can't drain. Abscesses can happen almost anywhere on your body.

Treating a Wound When Pus Is Present

Resist the urge to scrub a surgical wound that has pus coming from it. You may want to get the area as clean as possible, but you could do more harm than good. Instead, tell your surgeon that there is an infection at the surgical site. Don't clean it or try to remove the pus.

The surgeon may need to swab the site. This is for a wound culture, which helps determine the nature of the infection and which antibiotic will be most helpful.

You may need antibiotics, a change in your wound care regimen, or both. Often, you'll be given an antibiotic at the first sign of infection. If a culture indicates another antibiotic may work better, your doctor may have you switch.

If you can't get an appointment right away and must clean the site, gently wash it with warm water and a gentle cleanser. Rinse well. Don't scrub or use harsh cleansers, which can irritate the wound. If it's too harsh for a baby's skin, don't use it.


A surgical incision may become infected. When this happens, pus may appear at the site. It is also possible for an incision to have normal drainage. Your surgeon will be able to tell the difference.

Infections can become serious quickly, so notify your surgeon right away if you see anything that looks like pus in your incision. Your surgeon may swab the site to identify the nature of the infection. You will likely need to take antibiotics until it clears up.

A Word From Verywell

Some drainage is normal after surgery, but it can be hard to tell whether drainage is a sign of infection or just fluid. 

If you have drainage coming from your incision, call your surgeon right away. It is far better to call and find out that there's no need to worry than to ignore something that could become serious.


3 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  2. Gyawali B, Ramakrishna K, Dhamoon AS. Sepsis: The evolution in definition, pathophysiology, and managementSAGE Open Med. 2019;7:2050312119835043. doi:10.1177/2050312119835043

  3. Schmitz G, Goodwin T, Singer A, et al. The treatment of cutaneous abscesses: comparison of emergency medicine providers' practice patterns. West J Emerg Med. 2013;14(1):23–28. doi:10.5811/westjem.2011.9.6856

By Jennifer Whitlock, RN, MSN, FN
Jennifer Whitlock, RN, MSN, FNP-C, is a board-certified family nurse practitioner. She has experience in primary care and hospital medicine.