Chronic wounds differ from typical injuries by failing to progress through normal healing stages. A wound is classified as chronic if it shows no substantial improvement within three months. This prolonged healing transforms a simple injury into a complex health concern affecting millions. Chronic wounds significantly impact a person’s life, extending beyond the physical wound to influence overall well-being.
Common Types and Underlying Causes
Venous leg ulcers are the most common type of chronic wound, often stemming from venous insufficiency. Faulty valves in leg veins cause blood to pool and increase pressure. This sustained pressure damages skin blood vessels, making them fragile and susceptible to breakdown.
Arterial, or ischemic, ulcers develop from poor blood circulation, primarily caused by peripheral artery disease (PAD). In PAD, narrowed or blocked arteries deprive tissues of oxygen, leading to damage and painful, “punched-out” wounds, usually on the lower extremities.
Diabetic foot ulcers are common in diabetes, resulting from nerve damage (neuropathy) and impaired blood flow. Neuropathy leads to loss of sensation, so injuries go unnoticed. Damaged blood vessels reduce circulation, hindering healing and infection fighting.
Pressure ulcers, commonly known as bedsores, form from prolonged pressure on skin, particularly over bony areas. This pressure interrupts blood supply, causing tissue damage and eventual death. Individuals with limited mobility, such as those bedridden or in wheelchairs, are susceptible to these wounds on areas like the tailbone, heels, or hips.
Why Chronic Wounds Fail to Heal
Chronic wounds often remain in a prolonged inflammatory state, unlike acute wounds where inflammation is temporary. The body continuously sends inflammatory cells, which can damage healthy tissue and prevent the wound from entering the rebuilding phase. This sustained response disrupts the biochemical signals needed for repair.
Bacterial biofilms are organized communities of bacteria in a protective matrix, highly resistant to antibiotics and immune defenses. Biofilms form rapidly, creating persistent inflammation and infection, stalling healing.
Poor oxygen and nutrient supply, known as hypoxia, contributes to non-healing. While conditions like PAD cause systemic poor circulation, at the wound site, lack of oxygen prevents cells from generating energy for tissue repair. This localized deficiency impairs cell function and new tissue production, hindering wound closure.
Senescent cells, “old” or dysfunctional, accumulate at chronic wound edges. These cells stop dividing but remain active, secreting pro-inflammatory factors that worsen inflammation and disrupt the wound. Their presence impedes healthy cell and stem cell proliferation, contributing to non-closure.
Medical Management and Treatment
Debridement involves removing dead, damaged, or infected tissue to create a clean wound bed and promote new tissue growth. Methods include surgical debridement for rapid removal and autolytic debridement, using the body’s enzymes under a moisture-retentive dressing to slowly break down necrotic tissue.
Advanced wound dressings create an optimal healing environment.
- Hydrocolloid dressings form a gel to maintain a moist environment, beneficial for wounds with light to moderate drainage.
- Alginate dressings, derived from seaweed, are highly absorbent for heavily exuding wounds and transform into a gel upon contact with fluid.
- Foam dressings provide cushioning, absorb excess fluid, and protect the wound.
- Antimicrobial dressings, often containing silver or iodine, help control bacterial load.
Advanced therapies are used for complex chronic wounds. Negative Pressure Wound Therapy (NPWT), or a wound vac, uses suction to apply controlled negative pressure. This removes excess fluid, reduces swelling, increases blood flow, and draws wound edges together, stimulating tissue growth.
Compression therapy is a cornerstone for treating venous leg ulcers, involving specialized bandages or stockings to improve blood flow back to the heart and reduce swelling.
Off-loading techniques are important for diabetic foot ulcers and pressure ulcers, redirecting pressure away from the wound using specialized footwear, casts, or cushions.
Hyperbaric oxygen therapy, an intensive option, involves breathing pure oxygen in a pressurized chamber, significantly increasing oxygen delivery to tissues to promote healing and fight infection, especially in wounds with poor oxygen supply.
Potential Complications
Chronic wounds risk severe infection, which can escalate from localized cellulitis to life-threatening sepsis. Sepsis is an overwhelming immune response to infection, causing widespread inflammation, organ damage, and potential death. Older adults and those with weakened immune systems are particularly susceptible.
Osteomyelitis, a bone infection, arises when bacteria from a chronic wound spread to underlying bone. This condition is challenging to treat, often requiring prolonged antibiotics and surgery to remove infected bone. Diabetic foot ulcers have a heightened risk of leading to osteomyelitis in the foot bones.
In severe cases, if infection is uncontrolled or tissue viability is compromised, amputation of the affected limb may be necessary. This prevents life-threatening infection spread or removes non-viable tissue. Chronic wounds, especially diabetic ulcers, precede a large percentage of lower extremity amputations.
Beyond physical complications, chronic wounds profoundly affect quality of life. Patients experience chronic pain, leading to sleep disturbances and reduced mobility. The persistent nature of these wounds also results in significant psychological and social burdens, including anxiety, depression, and social isolation.