When a surgical wound appears red, is it an indication of infection or fat necrosis?

A red surgical wound can signal either a postoperative infection or fat necrosis, and distinguishing between them requires evaluating additional signs and symptoms.

Key differences at a glance:

• Infection: Redness spreads outward, wound feels warm, may drain pus or cloudy fluid, often accompanied by fever, increasing pain, or swelling.
• Fat necrosis: Redness is localized, a firm lump may form under the skin, usually painless, no fever, and drainage (if any) is oily or yellowish.

Because these conditions can look similar but require very different treatments, it's important not to guess. Early identification of an infection can prevent serious complications, while recognizing fat necrosis can spare you unnecessary worry and interventions.

If you're noticing redness around a surgical wound, take a few minutes to complete a free, instant, online symptom check. It's an easy, private way to better understand what your symptoms may mean and decide on the right next steps—whether that's monitoring at home or seeking urgent care.

Reviewed for medical accuracy: 07/20/2026