The Four Stages of Healing
Posted on Jun 05, 2020

Harness your body's healing cycle & improve overall foot health.


Hi, Dr. Meredith Warner here -

As an orthopedic surgeon, I not only specialize in surgical procedures - but also have to be an expert in the process of healing. Surgery is simply a means to the end - and the goal of each procedure is healing and the promotion of better form and function. I’d like to share a little bit of what I know about the physical process of healing with you today:

There are four main phases of healing that are universal and generally follow the same pattern and timing no matter what. If there is variation, that is when there are problems. Diabetics, for example, have differences in timing between the four phases of healing, which makes their wounds heal slower or become chronic.

Connective tissue is the stuff that puts a human together and makes the body “stick” together - not just tendons and ligaments. Connective tissue can be bone, ligament, nerves, muscles, tendons, and the matrix (surrounding gel/fluid) that holds the cells in place. Its universality throughout the structures of the body serves as a reminder for the interconnectedness of the healing cycle.

When connective tissue is injured, the collagen must be reformed and the structure of the material (skin, tendon, ligament, etc.) must be re-formed. The human body uses a four-step process that reliably achieves these goals if the environment is right.

The four phases of healing are hemostasis, inflammation, proliferation, and remodeling.


Just after an injury, the body is in a default mode to protect and survive. If, for example, an injury results in bleeding, the body stops the bleeding in an effort to preserve the tissue and save energy for possible fight or flight. The body does this primarily through the process of clotting. A clot is a clump of platelets and inflammatory cells that are the first to arrive at the site of injury. They are called to the area by a complicated system of signals released into the bloodstream as soon as an injury occurs.

At the scene of the wound - be it a cut, laceration, contusion, burn, chemical exposure, tear, or any other damage - the platelets bind the exposed collagen of that tissue within the extracellular matrix. Once bound, the platelets begin to work.

Platelets are magical fragments of cells in the bloodstream with awesome healing capacity. These begin to immediately secrete sphingosine-1-phosphate, thrombospondin, fibronectin, von Willebrand factor. These then stimulate even more platelet action, promoting a release of clotting factors, which stop the bleeding - by causing a matrix of fibrin to develop that acts as a plug. This stable clot/plug then acts as a bed for substances and cells flowing into the wound, because the platelets in a clot also secrete growth factors that are integral to the next steps in healing.

Once these growth factors are released by platelets into the wound environment, other cells like neutrophils and macrophages enter the zone. PDGF recruits cells that form fibrin (fibroblasts) and then collagen begins to be deposited - beginning the tissue repair process.


The hemostasis phase starts immediately after an injury and overlaps with the inflammatory phase of healing. The inflammatory phase should only last a few days.

If it persists, chronic inflammation results and then chronic non-healing or poorly healing tissue is the outcome. For now, we will focus on a normal inflammatory phase of healing.  

There is a group of signaling molecules in the bloodstream known as the ‘complement’ system. The complement system is activated at the time of the inflammatory phase. The system brings mediators that control the ‘leakiness’ of the surrounding blood vessels and also brings chemotactic factors. These in turn attract white blood cells (leukocytes) within 24-48 hours after the injury.

Mast cells ( a type of leukocyte) appear as well and release granules filled with histamine. This is what causes what we think of clinically as inflammation. Mast cells and histamines are directly responsible for the redness, warmth, heat, and pain of inflammation. Basically, the “leakiness” of the blood vessels in the region is increased by histamines and that allows for more healing and building cells to reach the zone of injury.

One of these cells is the neutrophil. Neutrophils remove bad things from the wound; they act to remove pathogens, damaged matrix, dead cells, and foreign material. Neutrophils do this by phagocytosis; this is literally the ‘eating’ of the bad stuff. These are early and aggressive cells that begin the process of healing. One can think of this aspect of wound healing like one thinks of the demolition phase of construction.

Next, monocytes and lymphocytes enter. These become macrophages. Macrophages are the workhorses of the demolition process. These cells remove the remaining dead and damaged tissues. The macrophages are more selective and powerful than the neutrophils and they do a more ordered and detailed “clean-up” of the damaged tissues.

Macrophages are also important because these cells also produce more healing factors. They make more TGF-beta, PDGF, Tumor necrosis factor-alpha (TNF-a), and also cytokines like Il-6, Il-1. All of these growth factors and cytokines from macrophages act to cause the fibroblasts (fiber-forming cells) to grow along with smooth muscle and endothelial cells. Endothelial cells are lining cells for vessels and skin.  

Once the macrophages have finished cleaning up the injury site and started the healing and rebuilding process by providing the building blocks, they actually then remove the neutrophils - the cells that clean up debris and are one of the first cells that reach the injury. This is one way that scientists can mark the conversion from the inflammatory phase to the proliferative phase; they can count the neutrophils.  


The proliferation phase is the actual construction phase of the tissue. Here is where the connective tissue is made whole again.

The fibrin and fibrin matrix that was produced at the inflammatory phase is merely a scaffold for the actual tissue. It is ‘granulation’ tissue and must be converted to the actual tissue needed; this may be smooth skin, strong tendons, and ligaments, muscle, or bone. The fibrin is replaced by collagen. This process usually starts on day 2 or 3 after the injury or surgery.

Proliferation involves angiogenesis (forming of new blood vessels), tissue granulation, re-epithelialization (formation of skin), and wound contraction (making a wound small).  

The formation of new blood vessels is important because without blood nothing can heal. Blood brings oxygen and nutrition. Blood also allows for the efficient removal of waste. Different growth factors release that signal for this process to happen.

The growth factors that are released also stimulate “fibroblasts” which start the process of skin production. Skin building cells, called keratinocytes flow to the injury site through the bloodstream and enter from the edges of the wound. Fibroblasts come from bone marrow when they respond to the chemical signals released during the inflammatory phase. These produce a matrix that allows for tissue to build.  

Some fibroblasts will turn into ‘myofibroblasts.’ These have a muscular component and will literally pull the edges of the wound together to make it smaller as it heals.  


Wound remodeling is the last phase of healing. It usually starts at week 2 or 3 and can last for a year in some cases. In this phase, the tissue matures and becomes its true self.

Weaker collagen is replaced by stronger collagen. Disorganized tissue becomes organized. The organization process is regulated by the fibroblasts that secrete an enzyme that degrades the collagen matrix of the wound bed and allows for the realignment of that collagen into organized networks. That organization is modified by stress, load, pressure, gravity, and other mechanical and chemical forces. The key to good wound repair is the remodeling and re-organization of the extracellular matrix of the damaged tissue.


In my clinical practice, I have found that in most cases, functional recovery - movement as soon as possible after surgery, physical therapy, and massage - is the best way to quickly promote healing.

This is the methodology behind my design of The Healing Sole. Each feature of The Healing Sole is chosen to work together to offload stress, evenly distribute weight, and stretch + strengthen the muscles and tendons of the foot. My design not only allows the foot to rest, but it targets those regions of the foot that most commonly cause pain and gently recovers them with each and every step.

I am confident that you will find relief from your plantar fasciitis and other foot pain with my design - which is why I offer a 30-day satisfaction guarantee with every purchase. Try them out for up to 30 days; if you do not find relief within that time frame, simply return them to us for a refund.


Dr. Meredith Warner is the creator of The Healing Sole and Well Theory. She is a board-certified and fellowship-trained Orthopedic Surgeon and Air Force Veteran.

Dr. Warner has treated countless patients for heel pain and plantar fasciitis pain in her private practice, Warner Orthopedics and Wellness. She developed The Healing Sole so that wearers can harness the body's natural healing power and have an option for everyday relief, without the need for surgery or expensive medical intervention.