Wound Healing Phases & Closure Types

A surgical incision and a dehisced wound both heal — but through entirely different pathways on entirely different timelines. Knowing which phase the wound is in drives every nursing decision.

Wound healing follows four overlapping phases. Hemostasis (seconds to hours) activates platelets and fibrin to form a clot. Inflammation (1–6 days) brings neutrophils then macrophages to clear debris — redness, warmth, and edema are expected, not signs of infection. Proliferation (4–24 days) builds granulation tissue (beefy red, moist), contracts the wound, and re-epithelializes from edges inward. Maturation/remodeling (21 days to 2 years) reorganizes collagen; the scar never regains more than about 80% of original tensile strength. Closure type determines the trajectory. Primary intention: clean surgical wound, edges approximated, minimal scarring, fastest healing. Secondary intention: wound left open to granulate from the base up — larger scar, longer timeline, higher infection risk. Tertiary intention (delayed primary): wound initially left open for drainage or debridement, then closed surgically once clean. Nurses assess wound phase by tissue color and characteristics: red/granulating is proliferative, yellow/slough signals stalled healing needing intervention, black/eschar indicates necrotic tissue.

Key Distinctions

Don't confuse the expected inflammation phase (warmth, redness, mild edema peaking at days 2–3) with wound infection (purulent drainage, increasing pain, fever after day 5). Students mix up secondary and tertiary intention — secondary stays open permanently; tertiary is intentionally delayed then closed. Granulation tissue is beefy red and healthy; hypergranulation rises above wound edges and impairs closure.

Clinical Pearl

Red is ready, yellow is yucky, black is bad. Wound bed color tells you the healing phase and whether the wound is progressing or stalled.