Decubitus ulcers, more commonly called pressure injuries or bedsores, are areas of tissue damage caused by sustained pressure on the skin and underlying structures. They develop when soft tissue is compressed between a bony prominence and an external surface for too long, cutting off blood flow and starving cells of oxygen. The sacrum (lower back), heels, hips, and shoulder blades are the most frequent sites, though these wounds can form anywhere the body bears weight or sits against a surface. Up to three million patients in the United States are affected each year, making pressure injuries one of the most common and costly complications in hospitals and long-term care settings.1PubMed Central. Risk of readmissions, mortality, and hospital-acquired conditions across hospital-acquired pressure injury (HAPI) stages in a US National Hospital Discharge database
How Pressure Injuries Actually Form
The underlying cause sounds straightforward: too much pressure for too long. But the tissue damage involves several overlapping processes. When you press skin and muscle against bone, the tiny blood vessels feeding those tissues collapse, starving them of oxygen and nutrients. This ischemia is driven not just by direct compression but also by shear, the sideways force that occurs when skin stays in place while underlying tissue slides (as when someone gradually slumps down in a hospital bed).2PubMed. The effects of pressure and shear on capillary closure in the microstructure of skeletal muscles High tissue deformation begins killing cells at the microscopic level within minutes, though it can take hours of sustained loading before any visible damage appears on the skin surface.3PubMed Central. Our contemporary understanding of the aetiology of pressure ulcers/pressure injuries
Superficial damage tends to result from shear and friction at the skin’s surface. Deeper injuries, the kind that form over the sacrum or the heel bone, are more typically caused by a combination of high pressure and shear transmitted to deeper layers of muscle and fat sitting right above a bony prominence.4PubMed Central. Our contemporary understanding of the aetiology of pressure ulcers/pressure injuries This means a wound can actually start deep inside the body and only later become visible on the skin, which is part of what makes these injuries so treacherous.
Environmental factors also play a role. Elevated skin temperature and excess moisture, whether from sweating, incontinence, or wound drainage, change the mechanical properties of skin and increase metabolic demand in the compressed tissue, making damage more likely under the same amount of pressure.5PubMed Central. Effects of ambient conditions on the risk of pressure injuries in bedridden patients-multi-physics modelling of microclimate
Stages and What They Look Like
Pressure injuries are classified into stages that reflect how deep the damage goes. In stage 1, the skin is intact but shows a reddened area that does not turn white (blanch) when you press on it. Stage 2 involves a partial loss of skin thickness, often appearing as a shallow open wound or a fluid-filled blister. Stage 3 extends into the fatty tissue beneath the skin, creating a deeper crater, while stage 4 reaches down to muscle, tendon, or bone. There are also two additional categories: unstageable wounds, where dead tissue covers the wound bed and hides how deep it goes, and deep tissue injury, where the surface skin looks purple or maroon but the real destruction is happening underneath.
Deep tissue injury is particularly tricky to identify because the skin discoloration can resemble other conditions. In patients with lighter skin, the classic presentation is a defined area of purple or maroon tissue, sometimes with surrounding redness. In patients with darker skin tones, the traditional color changes are much harder to spot; clinicians are advised to look for persistent redness and areas of hyperpigmentation that do not blanch, rather than relying on color alone.6PubMed Central. Differential diagnosis of suspected deep tissue injury This diagnostic gap has real consequences: pressure injuries in people with darker skin are more frequently missed or misidentified, which delays treatment.
A range of other conditions can mimic a pressure injury, including incontinence-related skin breakdown, bruising, blood clots under the skin, and even rare infections like necrotizing fasciitis. Getting the diagnosis right matters because treatment for each is different.7PubMed Central. Differential diagnosis of suspected deep tissue injury
Who Gets Them and Why
Anyone who cannot move freely is at risk. The classic patient is an older adult confined to bed or a wheelchair, but the reality is broader than that. People under general anesthesia during long surgeries, patients in intensive care units, and anyone immobilized by injury or illness can develop a pressure wound in a surprisingly short time. The most widely used screening tool, the Braden Scale, evaluates six factors: sensory perception, moisture exposure, physical activity level, mobility, nutritional status, and friction or shear.8PubMed Central. Predictive validity of the braden scale for pressure injury risk assessment in adults: A systematic review and meta‐analysis Lower scores mean higher risk.
Nutrition deserves special attention because it is one of the most modifiable risk factors. Poor dietary intake directly interferes with the immune response, slows collagen production, and weakens the tensile strength of healing tissue.9PubMed Central. Pressure Ulcer and Nutrition Hospitalized patients are often already malnourished on admission, and the metabolic stress of illness makes things worse. Ensuring adequate protein, calories, and micronutrients (especially zinc and vitamin C) is a standard part of any pressure injury prevention and treatment plan.
Medical devices are another underappreciated source of risk. While most people picture a bedsore developing on the tailbone or heel, pressure injuries can form beneath any object pressing against the skin: oxygen masks, cervical collars, casts, splints, and tubing. The National Pressure Ulcer Advisory Panel recognizes that pressure ulcers can develop under any device applying sustained pressure.10PubMed Central. Medical device related pressure ulcers in hospitalized patients Hospital staff increasingly check under devices during routine skin assessments, but device-related pressure injuries remain common, especially in critical care settings where patients are attached to many pieces of equipment simultaneously.
Prevention in Practice
The single most important preventive measure is regularly changing a patient’s position. Turning and repositioning redistribute pressure across different parts of the body, allowing compressed tissue to recover blood flow.11PubMed Central. Turning and Repositioning Frequency to Prevent Hospital-Pressure Injuries Among Adult Patients: Systematic Review The traditional guideline of repositioning every two hours is deeply embedded in nursing practice, though recent research has explored whether slightly different intervals might work for certain patients using high-quality support surfaces. Regardless of timing, the principle is the same: keep sustained pressure from building up on any one spot.
Support surfaces, the mattresses and cushions a patient lies or sits on, are another major line of defense. Not all surfaces are equal. Reactive air mattresses, which conform to the body and distribute weight more evenly, appear to cut the rate of new pressure injuries roughly in half compared with standard foam mattresses, based on limited evidence.12PubMed Central. Reactive air surfaces for preventing pressure ulcers Alternating pressure mattresses, which cycle air through different chambers to shift pressure points mechanically, are another option, though their advantage over reactive surfaces is less clear. Choosing the right surface depends on the patient’s risk level, weight, and mobility.
Other prevention basics include keeping skin clean and dry, managing incontinence promptly, padding bony prominences, and maintaining good nutrition. None of these steps is glamorous, and they require consistent effort from nursing staff, caregivers, and the patient when possible. That consistency is the hard part.
Treating an Established Wound
Once a pressure injury has formed, treatment aims to create the right conditions for the body to heal itself. The first priority is offloading: removing all pressure from the wound. Beyond that, wound care involves keeping the wound bed moist, removing dead tissue, managing infection, and choosing the right dressing.
Debridement, the removal of dead tissue, scabs, biofilm, and other debris from the wound, is a foundational step. Necrotic material slows healing, harbors bacteria, and can mask the true depth of the wound. Proper debridement improves blood flow to the wound area, reduces inflammation, and lowers infection risk.13PubMed Central. Wound debridement products and techniques: clinical examples and literature review There are several methods, from sharp debridement with a scalpel to enzymatic agents that chemically dissolve dead tissue, and the choice depends on the wound’s characteristics and the patient’s tolerance.
Biofilm, a slimy layer of bacteria that colonizes chronic wounds, is a significant barrier to healing. Research on chronic pressure ulcers has shown that wounds where biofilm is successfully eliminated after debridement heal substantially better than those where biofilm persists.14PubMed Central. Rapid detection of biofilm by wound blotting following sharp debridement of chronic pressure ulcers predicts wound healing Biofilm re-forms quickly, which is why repeated or maintenance debridement is often necessary for chronic wounds.
Dressings play a bigger role than simply covering the wound. A network meta-analysis comparing multiple dressing types found that foam dressings, hydrocolloid dressings, silver ion dressings, biological wound dressings, and polymeric membrane dressings all outperformed plain sterile gauze in healing pressure injuries.15PubMed Central. Efficacy of different types of dressings on pressure injuries: Systematic review and network meta‐analysis Among these, polymeric membrane dressings showed the strongest advantage over gauze. However, when hydrocolloid dressings were directly compared with other advanced dressings in a separate meta-analysis, no clear winner emerged between them.16Revista Latino-Americana de Enfermagem. The effectiveness of hydrocolloid dressings versus other dressings in the healing of pressure ulcers in adults and older adults: a systematic review and meta-analysis The takeaway is that almost any modern wound dressing is better than plain gauze, but the differences among advanced dressings are often small and may come down to wound characteristics, cost, and ease of use.
When Standard Care Is Not Enough
For wounds that fail to respond to offloading, debridement, and dressings, clinicians turn to more aggressive interventions. Negative pressure wound therapy (sometimes called vacuum-assisted closure, or VAC therapy) applies controlled suction to the wound through a sealed dressing. This pulls excess fluid out of the tissue, reduces bacterial load, improves blood flow, and stimulates the growth of new tissue. It tends to reduce wound volume and depth faster than conventional dressings and can sometimes make the difference between needing reconstructive surgery and not.17PubMed Central. Vacuum assisted closure (VAC)/negative pressure wound therapy (NPWT) for difficult wounds: A review In patients with spinal cord injuries and pressure ulcers, negative pressure therapy has been shown to accelerate reduction in wound size and speed up the formation of healthy granulation tissue compared with standard care.18PubMed Central. The Role of Vacuum Assisted Closure in Patients with Pressure Ulcer and Spinal Cord Injury: A Systematic Review
Stage 4 pressure ulcers, where bone, tendon, or muscle is exposed, often require surgical reconstruction. Flap cover surgery uses a section of well-vascularized tissue, often muscle with overlying skin, to fill the wound defect and provide durable coverage. Flaps reduce the risk of bone infection (osteomyelitis) and offer more reliable long-term healing than conservative wound care for these deep wounds.19International Journal of Africa Nursing Sciences. Flap cover for pressure ulcer However, flap surgery is a major procedure, and recurrence rates after reconstruction remain a concern, particularly for patients who cannot change the underlying conditions that caused the wound in the first place.
Research into stem cell and exosome-based therapies is in early stages but is generating interest. In animal studies, exosomes derived from embryonic stem cells have accelerated wound closure and promoted new blood vessel growth in pressure ulcer models, partly by reversing the aging of endothelial cells in the wound bed.20PubMed Central. Human embryonic stem cell-derived exosomes promote pressure ulcer healing in aged mice by rejuvenating senescent endothelial cells Reviews of stem cell approaches suggest these therapies could eventually become an option for patients with difficult-to-treat ulcers, particularly those with spinal cord injuries, though human clinical evidence is still limited.21PubMed Central. Stem cell and tissue engineering approaches in pressure ulcer treatment
Spinal Cord Injury and Neonates
People with spinal cord injuries face a uniquely high and lifelong risk. The paralysis and sensory loss mean they cannot feel the early warning signs of pressure damage (pain and discomfort that would prompt a person to shift position), and they often cannot reposition themselves without help. Beyond the loss of movement and sensation, spinal cord injury disrupts autonomic function, circulation, and metabolism in ways that further weaken tissue resilience.22PubMed Central. Pressure Injuries and Management after Spinal Cord Injury Pressure injuries are among the leading causes of rehospitalization in this population, and many patients deal with recurrent wounds throughout their lives. Prevention for spinal cord injury patients centers on specialized wheelchair cushions, rigorous skin inspection routines, pressure-relief techniques (such as regular weight shifts), and education for both patients and caregivers.
At the other end of the age spectrum, neonates in intensive care are also surprisingly vulnerable. Premature infants have very little subcutaneous fat, especially before about 32 weeks of gestation, which means pressure can be transmitted directly to deeper tissue with almost no cushioning. In critically ill, immobile, and sedated newborns, pressure injuries are most commonly seen on the back of the head (occiput) and the ears, because infants’ heads are proportionally large and heavy.23PubMed Central. Pressure Injury Incidence and Risk Factors in Neonates Undergoing Surgical Intervention: A Prospective Study Medical devices such as CPAP masks and pulse oximetry probes are frequent culprits. Neonatal skin assessment requires a different mindset than adult care, given the fragility of the skin and the different distribution of at-risk body sites.
The Financial and Institutional Burden
Pressure injuries are not just a clinical problem; they are one of the most expensive complications in modern healthcare. One analysis of a national hospital discharge database found that the average additional cost associated with a hospital-acquired pressure injury was roughly $22,000 per case. Patients with these injuries stayed in the hospital nearly four extra days and had 1.5 to 2 times the risk of being readmitted within 30 to 90 days. Higher-stage injuries were associated with greater costs, longer stays, and increased in-hospital mortality.24PubMed Central. Risk of readmissions, mortality, and hospital-acquired conditions across hospital-acquired pressure injury (HAPI) stages in a US National Hospital Discharge database A separate study found that the total hospitalization cost per patient with a stage 4 ulcer exceeded $124,000.25PubMed Central. High Cost of Stage IV Pressure Ulcers
These numbers have driven significant policy changes. In the United States, the Centers for Medicare and Medicaid Services stopped reimbursing hospitals for the added costs of certain hospital-acquired pressure injuries, effectively making them a financial penalty for the institution. The logic is that most pressure injuries acquired during hospitalization are preventable with proper care, and hospitals should bear the cost when prevention fails. This policy has pushed hospitals to invest more heavily in prevention programs, specialized mattresses, skin assessment protocols, and nursing education, though the effectiveness of financial penalties as a motivator for quality improvement is still debated. Another study of hospital-acquired pressure injuries found that affected patients had significantly higher total hospitalization costs and greater odds of readmission within six months.26PubMed. Assessment of Risk Factors Associated With Hospital-Acquired Pressure Injuries and Impact on Health Care Utilization and Cost Outcomes in US Hospitals
Artificial Intelligence in Wound Assessment
One of the practical challenges in pressure injury care is consistency. Different clinicians looking at the same wound can disagree on the stage, and staging errors can lead to inappropriate treatment decisions. Researchers have been exploring whether artificial intelligence applied to smartphone photographs can help standardize wound assessment. A pooled analysis of 21 studies found that AI models showed high overall diagnostic accuracy for pressure injury staging, with a sensitivity of about 74% and a specificity of 93%.27PubMed. Artificial Intelligence in Pressure Injury Diagnosis: A Critical Appraisal for Clinical Practice Accuracy varied by stage, with the highest performance for deep tissue injury and unstageable wounds, and somewhat lower accuracy for stage 2 injuries.
A real-time smartphone app using a deep learning model demonstrated the feasibility of bedside AI-assisted staging, though its overall prediction accuracy on a validation set was around 63%, well below what would be needed for independent clinical decision-making.28PubMed Central. An artificial intelligence-enabled smartphone app for real-time pressure injury assessment The technology is promising as a decision-support tool, particularly in nursing homes and home care settings where wound specialists are not always available. But it is not yet ready to replace trained clinical judgment, and the performance of these models on dark skin tones, where visual assessment is already most difficult, remains an area that needs much more validation.
Why the Name “Decubitus” Lingers
The word “decubitus” comes from the Latin decumbere, meaning to lie down, and it has been attached to these wounds for centuries. The 19th-century neurologist Jean-Martin Charcot used the term “decubitus ominosus” to describe pressure ulcers that appeared in patients with severe neurological disease, viewing them as an ominous sign of decline and impending death.29PubMed. Historical perspective on pressure ulcers: the decubitus ominosus of Jean-Martin Charcot For a long time, pressure ulcers were considered an inevitable consequence of serious illness, something that simply happened to bedridden patients and could not be helped.
That fatalistic view has been largely overturned. The modern understanding is that most pressure injuries, particularly those in earlier stages, are preventable with timely risk assessment and intervention, and that many can be reversed once identified.30PubMed. Historical perspective on pressure ulcers: the decubitus ominosus of Jean-Martin Charcot Terminology has shifted accordingly. Professional organizations now prefer “pressure injury” over “pressure ulcer” or “decubitus ulcer,” in part because the earlier terms implied that an open wound must be present, while the damage often begins deep under intact skin. You will still encounter “decubitus” in medical records, billing codes, and older literature, but in clinical practice the language is moving toward terms that more accurately describe what is happening: sustained pressure causing tissue injury, with or without a visible wound.