Wounds: Types, Causes, Symptoms, and the Four Stages of Healing

Definition

A wound is a disruption of the structural integrity of skin or other tissues caused by trauma, surgery, burns, infection, or bites.

Common Symptoms

• Bleeding
• Pain, tenderness
• Bruising, redness, swelling
• Inflammation, discoloration, deformity

Four Stages of Healing

1. Hemostasis (Bleeding & Clotting) – Vasoconstriction, platelet plug, fibrin clot.
2. Inflammatory/Proliferative – Neutrophils/macrophages clear debris; fibroblasts, angiogenesis, granulation tissue.
3. Migratory/Regenerative – Epithelial cells migrate across wound; collagen deposition.
4. Maturation/Remodeling – Collagen cross-linking, scar contraction, tensile strength increase (months to years).

Clinical Note

Chronic wounds stall in the inflammatory phase. Factors impairing healing: infection, diabetes, vascular disease, malnutrition, immunosuppression, smoking.