Wound Drainage: What Is Normal and When to Worry

Types of wound drainage

For a guide to what different colors mean in more detail, see wound discharge.

Normal drainage during healing

Healing goes through overlapping stages:

1. Inflammation (days 1 to 4): blood vessels leak plasma and white cells into the wound to clean it. Expect some clear or pink fluid, mild redness at the edges (less than about 1 to 2 cm), swelling and tenderness.
2. Proliferation (days 4 to 21): new tissue fills the wound. Drainage should decrease steadily. Surgical incisions closed with stitches usually stop draining within 2 to 3 days.
3. Remodeling (weeks to months): the scar strengthens and fades.

Larger open wounds, burns and wounds healing from the bottom up drain for longer.

Causes of abnormal wound drainage

Infection

A wound infection typically appears 3 to 7 days after an injury or surgery. Signs:

• cloudy, thick, yellow or green drainage
• a bad smell
• increasing pain, swelling, warmth and redness spreading from the wound
• red streaks, fever or chills
• the wound edges breaking down

After surgery this is called a surgical site infection. It may need antibiotics, opening and draining the wound, or both. An abscess is a walled-off pocket of pus that needs drainage.

Seroma

A seroma is a pocket of clear fluid that collects under the skin after surgery, especially after breast surgery, hernia repair, abdominoplasty or lymph node removal. It feels like a soft, fluid-filled swelling and may leak through the incision. Small seromas are absorbed over weeks. Large or uncomfortable ones are drained with a needle.

Hematoma

A collection of blood under the wound, causing swelling, bruising and dark red or brown drainage. It is more common with blood thinners. Large hematomas may need draining.

Fat necrosis and liquefied fat

After surgery in people with more abdominal fat, oily, yellowish drainage can come from damaged fat tissue. It is not necessarily infection but needs assessment.

Wound dehiscence

A sudden increase in salmon-pink drainage from an abdominal incision can be a warning that deeper layers are separating. See wound dehiscence.

Chronic wounds

Pressure ulcers, venous leg ulcers and diabetic foot ulcers often produce ongoing drainage. Heavy drainage can damage surrounding skin (maceration). See chronic wounds.

Surgical drains

Some operations leave a thin tube connected to a bulb (such as a Jackson-Pratt drain) to remove fluid. Typical care:

• Empty the bulb when it is half full, or as instructed, and record the amount and color.
• Drainage usually changes from red to pink to clear, straw-colored.
• The drain is usually removed when output falls below a set amount (often about 25 to 30 ml in 24 hours).
• Call your surgical team if drainage suddenly increases, turns cloudy or bright red, smells bad, or the tube falls out.

How to care for a draining wound

• Wash your hands before and after touching the wound.
• Follow your surgeon's instructions on when you can shower. Many incisions can be showered after 24 to 48 hours. Avoid soaking in baths, pools or hot tubs until it is closed.
• Change the dressing when it becomes wet, or at least once a day. A dressing soaked with drainage invites bacteria and damages skin.
• Use absorbent, nonstick dressings. Foam or alginate dressings help with heavier drainage.
• Protect surrounding skin with a barrier cream if it becomes white and soggy.
• Do not use hydrogen peroxide or alcohol in a healing wound.
• Eat enough protein, keep blood sugar controlled, and avoid smoking, all of which speed healing.

Frequently asked questions

Is it normal for a wound to drain clear fluid?

Yes. Small amounts of clear or pale yellow (serous) fluid are normal in the first few days of healing. The amount should decrease over time. A large or sudden increase in clear fluid after surgery may be a seroma and should be checked.

What does infected wound drainage look like?

Infected drainage is usually thick, cloudy, and yellow, tan or green, and may smell bad. It is often accompanied by increasing pain, redness, warmth and swelling around the wound, and sometimes fever. Contact your doctor promptly.

How long should an incision drain after surgery?

A closed surgical incision usually drains small amounts of clear or pink fluid for 2 to 3 days. Open wounds and those with drains can drain for longer. Drainage continuing beyond 5 to 7 days or increasing should be reviewed by your surgical team.

What is serosanguineous drainage?

Serosanguineous drainage is thin, watery, pink fluid made of plasma mixed with a small amount of blood. It is normal in the first days after surgery or injury. Bright red or heavy bleeding is not normal.

Should I cover a draining wound?

Yes. Cover it with a clean, absorbent, nonstick dressing to protect it from germs and to absorb fluid. Change the dressing whenever it gets wet or dirty. Keeping the wound moist but not soggy promotes healing.