Stages of Wound Healing

Wound healing is a natural body function by which by which the body repairs itself after injury. There are 3 basic stages:

1. Inflammatory Phase
2. Proliferation Phase
3. Remodeling and Maturation Phase

Inflammatory Phase

This stage begins immediately after injury and the body has stopped any further blood loss by coagulating (clotting.)

Once the blood loss has stopped, the body immediately goes into “first responder” mode and sends fluids containing plasma proteins, blood cells, and antibodies to the wound site. This fluid accumulation causes swelling, pain, fever, and redness while the wound is being efficiently sanitized by the body’s immune system.

Neutrophils (a type of white blood cell that is a first-responder of the immune system) and macrophages (a type of white blood cell that engulfs and digests cellular debris, foreign substances, and microbes) are also dispatched to the injury site to clean, scavenge for bacteria, and prepare the injury site for healing.

The Inflammatory Phase is the physiological equivalent of the body sending out the Fire Dept, Police Dept, and SWAT Team to the site of an emergency. It is a highly coordinated and efficient deployment to secure the area and bring the situation under control so that when the repair crew shows up in a couple of days, it can get right to work.

This phase lasts 2 to 6 days after the injury, most of the pain will subside when the inflammation reduces naturally and the body begins to heal. If the surgeon used a long-acting anesthetic in the wound it is possible you will have no pain at all for the early part of the Inflammation Phase, only to have pain suddenly appear 3-4 days post-surgery.

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Proliferation Phase

The Proliferation Phase is all about the growth of new tissue; this stage overlaps with the ending of the Inflammatory Phase by a day or so.

As the inflammation is subsiding and the first responder crews are leaving the site, the body sends in the repair crews and begins mending the injury. Fibroblasts (the conductors who orchestrate tissue repair) have begun to arrive and collect in the wound by around day 3 after the injury; this marks the start of the transition from Inflammatory Phase to Proliferation Phase.

By the end of the first week of the Proliferation Phase, granulation tissue (new tissues and blood vessels) can be seen in the wound; this tissue will continue to grow until the wound is healed. Granulation tissue is normally bright red, moist, soft to the touch, and has a bumpy appearance.

For patients going through open healing, these masses of granulation tissue keep growing along the bottom and sides of the wound until the cavity fills in and closes up. In closed wound surgery the granulation tissue forms along the walls of the wound and mends together in the middle when the walls meet; the process will be hidden from view under the stitches.

By about day 5 you will begin to notice different types of drainage from the wound; these are called exudate and are the by-product of healing and tissue repair. There are several different types of exudate, which we cover on the Drainage page.

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Remodeling and Maturation Phase

This stage overlaps with the Proliferation Phase towards the end of healing; it is the process of remodeling of the collagen fibers laid down in the Proliferation Phase and can last for up to 2 years after healing.

During this stage the nerve endings are re-growing and tissue is rearranging itself. In short, there is a lot of activity still happening long after your wound has healed on the surface. You may continue to feel tugging and tension from deep inside the wound for quite a while as the new tissue stabilizes. This will be a time when Pilonidal Paranoia strikes! Every twitch from the wound will send you into a panic, everyone goes through it.

This final phase continues for 18 months to 2 years after your wound has closed.

Additional Reading:

The Ethicon Wound Closure Manual (230 pages!)

Principals of Wound Healing – Canadian Assoc. of Wound Healing

Scar Tissue

The final result of wound healing is scar tissue.

Sometimes, the body will get a little gung ho and over heal. This builds up too much scar tissue and usually your surgeon will use the much dreaded Silver Nitrate to burn off the excess scar tissue. This usually happens in the final stages of healing and it is applied via a long Q-Tip. Some people barely notice and others will feel a burning sensation for hours. Silver Nitrate is also sometimes used to spur healing in a wound that has slowed or stopped. Also see the You and Your Scar page for more about your healed scar.