If you've ever cut your finger, you noticed that it started to bleed and there was some redness and swelling. Within a few minutes, the cut stopped bleeding; and, by the next day, you noticed a scab. And, within a week or so, the scab fell off and the cut was healed.
Well, what you actually observed were the 3 phases of your body's wound healing process.
When your skin was wounded, complete with flowing blood and broken skin, your body triggered a coordinated repair and healing process to quickly close the wound and rebuild your skin.
First, red blood cells form a blood clot, which helps stop the bleeding and creates a temporary barrier (a scab) that prevents pathogens from getting into the open wound. A few hours later, your skin might turn red and look swollen. This is called the inflammation phase, when the body sends white blood cells to capture and fight off any pathogens and prevent infection.
The white blood cells engulf debris and microorganisms, providing the first line of defense against infection. Other white blood cells scavenge tissue debris while macrophages stimulate cell migration, proliferation, and formation of the tissue matrix.
Next, fibroblast cells enter the wound, dropping off collagen and generating granulation tissue, which supports the new blood vessels (angiogenesis). This forms new connective skin tissue to replace what was there before. You may notice a red-pinkish color of the skin -- this is known as granulation. This is called the proliferation phase.
Finally, new collagen forms and includes a reorganization of new collagen fibers, forming a more organized lattice structure that progressively continues to increase tensile strength. As a result, the dermis and epidermis connect and contract to close the wound, forming a scar.This is the remodeling phase.
Note: The inflammatory phase can persist due to infection, nutritional deficiencies, and/or use/misuse of medications (i.e. antibiotics, steroid, alcohol) which may harm the new skin cells.
FYI: The next blog post will discuss wound dressings and how to properly care for a wound and prevent complications such as infection, fever and amputation.