Types of Drainage From a Surgical Wound

If you or a loved one has had surgery recently, you may be concerned about the surgical incision site—how to care for it, what it looks like, and if it appears to be healing properly. One thing to be aware of is drainage from the site, known as exudate. While it can be alarming to see drainage from a surgical wound, usually it's perfectly normal and even expected.

That said, in some cases, drainage can be a sign of infection—something that's fairly easy to prevent by taking simple steps like proper handwashing. Keeping an eye out for early signs of infection is also important, as the earlier infection is identified the faster it can be treated, which reduces healing time.

Exudate from a surgical wound can tell you a lot about whether the site is healing properly or not. Here are some differences between normal and abnormal wound drainage that can help you to evaluate if you should alert your doctor that something is wrong.

Here's a closer look at the various types of normal exudate.

Serous exudate: This type of fluid is normal from a wound in the early stages of healing, typically in the first 48 to 72 hours after the incision is made.

In some cases, serous fluid can actually weep from the skin, even where there is no trauma or incision. This typically happens in response to severe pitting edema due to a medical condition or after massive amounts of fluid are given, such as during treatment for severe trauma.

Serosanguinous drainage: This thin, watery drainage is composed of both blood and serum and may appear slightly pink from the small number of red blood cells that are present. This discharge is normal in the early stages of healing, as the blood is present in small amounts. It is important to keep in mind that a very small percentage of blood in the fluid can make serum appear pink.

These descriptions of exudate that indicate there may be a problem with how a surgical wound is healing can help you know if you should see your surgeon.

Bloody/sanguineous drainage: This is abnormal wound drainage that typically has a larger amount of blood present than in serosanguinous drainage. This bloody drainage is not typical of a healing wound and may indicate that the wound hasn't been treated gently enough during incision care, the patient is being too active too quickly after surgery, or another type of stress is affecting the incision site. Report this type of drainage to your surgeon.

Mostly/all blood: Hemorrhage is the term for severe bleeding from a wound that can be life-threatening, depending on the amount of blood loss, how difficult the bleeding is to control, how long the bleeding goes unchecked, and other injuries. The term hemorrhage refers specifically to blood being lost at a rapid rate. Medical attention is an absolute necessity for treating hemorrhages and may include blood transfusions and fluid resuscitation. In terms of drainage, hemorrhage is pure blood or nearly all blood. Seek treatment immediately.

Colorful drainage: Purulent drainage, better known as pus, is not a normal finding in an incision. This type of drainage can be a variety of colors, including white, yellow, grey, green, pink, and brown. Assume that this type of drainage is a sign of infection until proven otherwise. Color alone does not indicate infection, but a change from clear drainage to colorful drainage should be reported to the surgeon.

Foul-smelling drainage: In addition to being a variety of colors, purulent (pus) discharge may also have unpleasant or foul smells. While this smell is not always present, it is typical of this type of infection. Foul-smelling discharge should not be ignored as it is never considered normal. Clear discharge with a foul odor should be considered a sign of infection until proven otherwise.

While the type of drainage is important, the amount of drainage may be more important, depending upon the type. For example, if there is a small amount of bleeding from a wound, it may not be alarming, but blood gushing from a wound, known as hemorrhage, is a life-threatening condition.

A Word From Verywell

It can be a nerve-wracking thing, having a surgical wound, but that doesn't mean there is something to worry about. Normal wounds have normal drainage—it's clear or there is a little bit of blood or color—and it seems to get better day after day, or at least week after week. Abnormal wounds look angry and have angry drainage. They get worse—more tender, more drainage, more swelling—and they also feel worse most of the time.

Sometimes these angry wounds get worse quite quickly, and when that happens there is no denying the need for medical intervention. Trust your instincts and call your medical provider in this case.