1. Hemostasis (Stopping the Bleeding)
- Duration: Immediate to 2 days
- Key Processes:
- Vasoconstriction reduces blood flow.
- Platelets form a plug at the injury site.
- Fibrin stabilizes the clot to prevent further bleeding.
- Purpose: Establishes a barrier to blood loss and provides a foundation for tissue repair.
2. Inflammation (Cleaning the Wound)
- Duration: 2–5 days
- Key Processes:
- White blood cells (neutrophils and macrophages) clear debris and bacteria.
- Redness, swelling, and warmth occur due to increased blood flow.
- Growth factors are released to stimulate tissue repair.
- Purpose: Protects against infection and prepares the wound bed for healing.
3. Proliferation (Tissue Formation)
- Duration: 4 days to 3 weeks
- Key Processes:
- Fibroblasts produce collagen and extracellular matrix (ECM).
- Angiogenesis forms new blood vessels.
- Granulation tissue fills the wound bed.
- Reepithelialization occurs as skin cells migrate over the wound.
- Purpose: Rebuilds tissue and restores vascular supply.
4. Remodeling/Maturation (Strengthening the Tissue)
- Duration: Weeks to years
- Key Processes:
- Type III collagen is replaced by stronger Type I collagen.
- Myofibroblasts contract the wound edges.
- Scar tissue forms, regaining up to 80% of original tensile strength.
- Purpose: Enhances structural integrity of repaired tissue.
PLEASE REFER TO THIS EDUCATIONAL VIDEO: STAGES OF WOUND HEALING
References:
- Frontiers in Immunology. (2024). Recent advances in molecular mechanisms of skin wound healing. Retrieved from https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2024.1395479/full
- Royal Society Publishing. (2020). Wound healing: cellular mechanisms and pathological outcomes. Retrieved from https://royalsocietypublishing.org/doi/10.1098/rsob.200223
- Medscape Reference. (2024). Wound Healing and Repair – Categories of Wound Healing. Retrieved from https://emedicine.medscape.com/article/1298129-overview