How does wound healing work?
After an injury, accident or operation, wound healing is a complicated process involving many different cells, messenger substances and other substances. It aims to close a wound – i.e. a defective area in the tissue of the external or internal body surfaces – as quickly as possible. This prevents infections, temperature fluctuations, dehydration and other mechanical irritations from affecting the tissue.
There are basically two types of wound healing: primary and secondary wound healing.
Primary wound healing
Primary wound healing is found in uncomplicated occasional wounds, such as cuts and lacerations, with smooth wound edges and without major tissue loss. In this case, the wound must not be more than four to six hours old when it is closed. Wound healing after surgery is also primary if it is a non-infected (aseptic) surgical wound.
Secondary wound healing
Large and/or gaping wounds with major tissue loss heal secondarily, i.e. the wound edges do not grow together directly. Instead, the wound is filled from the base by granulation tissue. Such a secondarily healing wound ultimately has a wider scar surface, which is not very stable under stress and is often cosmetically unpleasant.
Secondary wound healing also occurs in chronic wounds such as diabetic foot ulcers or pressure sores (bedsores).
How can wound healing be accelerated?
It takes some time for the body to close wounds again. However, there are various ways to support wound healing.
Zinc ointment promotes wound healing, for example after burns, diabetic foot ulcers or following an operation.
Silver ions have an antibacterial effect. Silver powder or wound dressings containing silver are therefore used to prevent infections and thus have a positive effect on wound healing.
Many people use home remedies such as chamomile tea or tea tree oil to promote wound healing. There are initial indications that honey may accelerate wound healing.
Nutrition also plays an important role in wound healing. The body needs minerals such as iron and zinc, vitamins such as vitamin C or vitamin E and, in particular, proteins to keep the skin healthy and heal wounds. Proteins and their components, the amino acids, are needed to produce new tissue following an operation, for example.
What doctors strongly advise against is the consumption of alcohol. Contrary to popular belief, it does not “disinfect” from the inside, but actually interferes with wound healing.
Home remedies have their limits. If the symptoms persist over a longer period of time and do not improve or even get worse, you should always consult a doctor.
What are the phases of wound healing?
There are roughly three phases of wound healing, which often overlap and run in parallel.
The exudation phase, also known as the cleansing or inflammation phase, begins immediately after the wound has formed.
Any bleeding is stopped by vasoconstriction and activation of the blood clotting cascade (formation of fibrin = protein fibers). Damaged vessel walls are sealed. The release of messenger substances such as histamine triggers a local inflammatory reaction, as a result of which, among other things, the wall permeability of the finest blood vessels (capillaries) increases. This causes increased blood plasma to leak from the wound area (exudation).
The duration of the exudation phase is usually up to three days.
Granulation or proliferation phase
In this second phase of wound healing, tiny blood vessels, known as capillaries, and connective tissue cells begin to grow into the wound bed from the wound edges and form a solid network. This vascular tissue is deep red, moist, shiny and granular on the surface. Doctors refer to this as granulation tissue (Latin granulum = granules).
The connective tissue cells produce precursors of collagen. These stabilizing protein fibres cause the wound to shrink – pulling the wound edges together and reducing the wound surface.
The granulation phase lasts around ten days.
Regeneration phase
The regeneration phase usually lasts several weeks to months. The scar only reaches its maximum resilience after about three months.
