What Is the Yellow Stuff in a Healing Wound? Slough vs. Normal Drainage
What is the yellow stuff in a healing wound?
The Quick Answer
The yellow substance is typically **slough**—a viscous, fibrinous necrotic tissue ranging from pale yellow to tan that adheres to the wound bed. Unlike clear serous fluid (a normal healing component), slough represents dead cellular debris that impedes healing by blocking new tissue growth and harboring bacteria. It requires clinical debridement for proper wound progression.
Why We Ask This
Patients often mistake yellow slough for normal healing discharge or infection pus, causing anxiety about whether their wound is worsening or if they've caused harm through improper care. This confusion frequently delays appropriate treatment seeking.
The Practical Science
Slough forms when the inflammatory phase extends beyond normal duration due to poor perfusion, biofilm presence, or infection. Histologically, it consists of denatured proteins, fibrin, and leukocyte remnants that physically block fibroblast migration and angiogenesis essential for tissue repair.
In Clinical Practice
During wound assessment, a clinician would gently probe the yellow tissue with a cotton swab—if it doesn't bleed and feels stringy or adherent rather than liquid, it's confirmed slough requiring debridement rather than simple cleansing.
References & Context
Slough: what does it mean and how can it be managed"The appearance of slough is typically a pale yellow, viscous fibrinous tissue and can range from yellow to tan, usually, but not always, covering the entire wound bed."