Wound healing is a precise biological process that repairs damaged tissue. When a wound is open, the body initiates a complex rebuilding effort, and the appearance of new tissue can often cause alarm. Granulation tissue is the new, soft, pink or red tissue that forms in the wound bed, representing a significant step forward in the healing journey. This article clarifies the fate of this new tissue and addresses the common concern about whether it is supposed to detach as the wound closes.
What Granulation Tissue Is and Its Immediate Role
Granulation tissue is a temporary, specialized tissue that forms during the proliferative phase of wound healing, typically three to five days after injury. It is recognized by its vibrant reddish-pink color, moist consistency, and granular appearance, caused by numerous microscopic blood vessel loops. Its primary function is to fill the defect, providing a temporary foundation for the skin to close over.
The tissue is composed of a provisional extracellular matrix containing fibroblasts and newly formed capillaries. The process of forming new blood vessels, known as angiogenesis, is a major feature of this stage and is responsible for the bright color due to abundant blood flow. These new vessels supply the wound with the oxygen and nutrients required to sustain the intense cellular activity of the repair process.
Fibroblasts synthesize and deposit a weak form of collagen (Type III collagen) to create a structural scaffold. This matrix acts as a temporary plug, replacing the initial blood clot and providing a protective barrier against infection. Some fibroblasts differentiate into myofibroblasts, specialized cells with contractile properties. Their presence is instrumental in pulling the wound edges inward—a process known as wound contraction—which reduces the injury’s size.
The Normal Transformation of Granulation Tissue
Granulation tissue is an intermediate stage of healing that does not separate or fall off the wound bed. Instead, it undergoes a gradual, internal process of transformation and maturation into scar tissue. This transition marks the shift from the proliferative phase to the final remodeling phase, which can continue for months or even years.
During maturation, the temporary structure of the granulation tissue is systematically broken down and rebuilt into a stronger, more permanent form. The high density of blood vessels that gave the tissue its bright color begins to regress, reducing the blood supply. Simultaneously, weak Type III collagen fibers are replaced by stronger, more organized Type I collagen fibers, the main structural protein of the skin.
After completing their role in wound contraction, myofibroblasts undergo programmed cell death, which reduces the tissue’s cellularity. This remodeling results in a final scar that is paler, less vascular, and flatter than the original granulation tissue. The change in appearance signals successful, internal progression toward a mature scar, not a physical shedding of material.
When Tissue Appearance Signals a Problem
If material detaches from a wound, it is almost certainly not healthy granulation tissue, but rather non-viable or abnormal tissue. Two common types of non-viable tissue are slough and eschar, which must be removed for healing to proceed. Slough is often yellow, tan, or gray, with a stringy or thick consistency. Eschar is typically a dry, leathery, black or brown crust of necrotic tissue.
When these dead tissues detach, it is a necessary step in cleaning the wound bed, often facilitated by autolytic debridement or medical intervention. Unlike living, functional granulation tissue, slough and eschar impede healing by harboring bacteria and physically obstructing the repair process. Their removal exposes the healthy, underlying granulation tissue, which is a positive sign.
Another abnormal presentation is hypergranulation, sometimes called “proud flesh,” where the tissue grows excessively above the level of the surrounding skin. This overgrowth is bright red and friable, meaning it bleeds easily with minimal contact. While the tissue is living, its excessive height prevents epithelial cells from migrating across the surface to close the wound.
Hypergranulation does not fall off but may require treatment, such as chemical cauterization or light pressure dressings, to regress to the skin level. If the wound shows signs of infection (increasing pain, foul odor, or thick discharge), or if there is persistent hypergranulation, seek medical advice for proper assessment and management.