A wound occurs when there is a break or opening in the skin or mucous membranes. Wound healing is a complex process that starts the moment an injury occurs and can continue for weeks or months.
There are three stages to wound healing:
The inflammatory stage:
This stage starts immediately after the injury occurs and lasts from two to five days.
During the inflammatory stage, in response to immediate bleeding, the blood vessels narrow (vasoconstriction). Platelets collect in the wounded area (platelet aggregation), and a clot forms with assistance from thromboplastin (clotting factor). Specialized inflammatory cells — neutrophils, macrophages and monocytes — are recruited to the wound site where they ingest cell debris, along with microorganisms, to clean the wound bed.
The proliferative stage:
This stage will begin about two days after the injury occurs, and can last as long as three weeks.
In the proliferative stage, blood vessels are regrown and skin cells called fibroblasts make collagens, which are important structural skin proteins. The wound edges start to knit together and there is regrowth of epithelial skin cells (epithelialization).
The remodeling stage:
This stage will begin about three weeks after the injury, and can last as long as two years.
In the remodeling or maturation stage, the new collagen forms a stronger, more formal structure. Epithelialization continues, and the wound is healed.
When wounds are healing slowly or appear not to be healing, the condition of the wound bed should be considered.
The first step is to assess the ability of the wound to heal. Consider these factors:
- Is the blood flow adequate?
- Is the person anemic or malnourished?
- Is the wound infected?
- Is the wound too wet or too dry?
- Are steroids being used (these may inhibit wound healing)?
- Treat any infection with the use of topical antibiotics or antimicrobial silver dressings.
Source: (Hess, Cathy Thomas. (2005). Clinical Guide: Wound Care (5th ed.). Ambler, PA: Lippincott Williams & Wilkins).