Healing runs four stages; chronic wounds stall
Every normal wound follows hemostasis, inflammation, proliferation, then remodeling that can last a year or two. Acute injuries ride that timeline; chronic ones stall, often past three months. Diabetes alone may leave up to one in four patients facing a non-healing wound sometime in life.
A wound is any break in living tissue, from sudden trauma or from slow disease such as diabetes or vessel failure. Acute wounds move through four phases: clotting in minutes to hours, inflammation for about one to three days, proliferation lasting days to a month, and remodeling that typically spans twelve months and may continue for two years. Open wounds expose deeper tissue; closed ones damage underneath while skin stays intact. Clinicians further sort by mechanism—incision, laceration, abrasion, puncture—and by sterility using systems such as the CDC surgical classes.
When healing arrests in any phase, the wound becomes chronic. Many clinicians treat lack of progress beyond three months as chronic. Diabetes impairs healing through high glucose, neuropathy, microvessel damage, and immune changes; feet are the most common site. Venous pooling or arterial shortage starves tissue of oxygen and fuels lasting inflammation, especially in the legs. Pressure ulcers can form after as little as two hours of immobility; U.S. staging runs from intact reddened skin at stage one to full-thickness damage reaching muscle or bone at stage four.
Contamination risk shapes surgical planning. CDC Class 1 wounds are clean and uninfected; Class 2 are clean-contaminated with controlled entry into tracts such as gut or airway; Class 3 are contaminated accidental or grossly soiled surgical fields; Class 4 are dirty or already infected. Evaluation tracks size, site, bed color, depth, dead tissue, edge shape, and surrounding skin. Healthy beds look pink with granulation; dark red bleeding beds or excess tissue can signal infection or stalled repair. Age, oxygen supply, stress, illness, and drugs all change how fast the sequence finishes.
Source: Wound
