Pressure Sores: Symptoms, Types, Causes and Treatment

Pressure sores, also known as pressure ulcers or bedsores, are a common yet often underestimated medical challenge, especially for those with limited mobility. These wounds can significantly impact quality of life, slow recovery, and increase healthcare costs. Understanding their symptoms, types, causes, and treatment options is crucial for prevention and effective management. In this article, we’ll explore these aspects in depth, using the latest research to provide an evidence-based perspective.

Symptoms of Pressure Sores

Pressure sores can develop quickly and may present subtly at first. Early detection is essential for effective intervention and to prevent complications. Recognizing symptoms at various stages helps caregivers and patients alike to seek timely help and optimize outcomes.

Stage	Appearance	Sensation/Signs	Source
Early	Redness, discoloration	Pain/tenderness, warmth, swelling	2 3 4
Intermediate	Blistering, open sores	May weep fluid, mild odor	3 4
Advanced	Deep ulcer, exposed muscle/bone	Necrosis, infection, foul odor	3 4 9
Healing	Reduced size, new tissue	Less pain, temperature change	3

Table 1: Key Symptoms of Pressure Sores

Recognizing Early and Late Signs

Pressure sores often begin as a noticeable area of redness or discoloration, particularly over bony areas such as the sacrum, heels, hips, or elbows. The skin may feel warm, firm, or boggy compared to surrounding tissue. Pain or tenderness is common in the initial stages, but in people with reduced sensation (e.g., spinal cord injury), these symptoms may go unnoticed 2 4.

Progression of Symptoms

As the sore develops, the skin may blister or form an open wound. Fluid leakage and mild odor may be present, indicating skin breakdown. In advanced stages, the ulcer deepens, potentially exposing muscle or bone, and necrosis (tissue death) can set in. Infection is a serious risk, often accompanied by a foul smell, increased pain, or surrounding redness and swelling 3 4 9.

Healing Indicators

Healing sores typically show reduced size, less exudate, and the formation of granulation tissue. Interestingly, thermography studies show that 'normal' healing sores have a temperature difference of about 2.5°C between the sore edge and surrounding skin, while indolent (slow-healing) sores have a difference of less than 1°C 3.

Types of Pressure Sores

Not all pressure sores are the same. Classification systems help guide treatment and predict outcomes. Understanding the various types and stages is key to targeted care.

Classification	Description	Depth/Tissue Involved	Source
Stage 1	Non-blanchable redness	Superficial skin	4 5
Stage 2	Blister/partial-thickness wound	Epidermis, dermis	4 5
Stage 3	Full-thickness skin loss	Subcutaneous tissue	4 5
Stage 4	Deep tissue damage	Muscle, bone involvement	4 5
Sinus Type	Narrow, tract-like ulcer	Deep, with sinus tract	5
Ulcer Type	Typical open sore	Varies by stage	5
Mixed Type	Combination of ulcer and sinus	Multiple tissue layers	5

Table 2: Types and Classifications of Pressure Sores

Stages of Pressure Sores

Most classification systems divide pressure sores into four stages based on tissue involvement:

• Stage 1: The mildest; skin remains intact but is red and non-blanching (does not turn white when pressed).
• Stage 2: Partial-thickness loss of skin, presenting as a blister or shallow open sore.
• Stage 3: Full-thickness tissue loss; the ulcer extends into subcutaneous fat but not to muscle or bone.
• Stage 4: The most severe; deep tissue loss with exposed muscle, tendon, or bone, often with significant necrosis 4 5.

Alternative Clinical Typing

Some clinical frameworks also describe pressure sores as sinus, ulcer, or mixed types:

• Sinus type: Characterized by narrow tracts that may extend deeply, often with a small superficial opening.
• Ulcer type: The classic open sore with varying depth.
• Mixed type: Combines features of sinus and ulcer types, often more complex and challenging to treat 5.

Special Considerations

Certain wounds, such as those over the sacrum (near the anus), are notably harder to treat due to dressing detachment and contamination, requiring specialized approaches 4.

Causes of Pressure Sores

Pressure sores result from a combination of physical forces and individual vulnerabilities. Appreciating the interplay of these factors is key to both prevention and management.

Factor	Description	Impact Level	Source
Pressure	Sustained force (intensity/duration)	Direct tissue damage	1 7 8
Shear	Sliding motion, distorts tissue	Worsens injury	8 9
Friction	Rubbing against surfaces	Superficial damage	8 9
Moisture	Excess skin wetness (sweat, urine)	Reduces skin integrity	8 9
Immobility	Inability to change position	Major risk factor	2 6 8
Nutrition	Poor intake, low albumin	Impairs healing	2 6 8
Sensory Loss	Diminished pain/pressure sensation	Delayed detection	2 6 8

Table 3: Major Causes and Contributing Factors for Pressure Sores

The Pressure-Ischemia Paradigm

The fundamental cause of pressure sores is prolonged, unrelieved pressure, especially over bony prominences. This pressure impedes blood flow (ischemia), depriving tissues of oxygen and nutrients. Earlier assumptions suggested that pressures as low as 35mmHg for two hours could cause injury, but experimental models show that normal tissue is more resilient, with muscle being more sensitive than skin. Nevertheless, underlying conditions—such as paraplegia, infection, or repeated trauma—lower tissue tolerance 1 7 8.

Shear, Friction, and Moisture

Shear occurs when skin moves in one direction while the underlying bone moves in another, such as when a patient slides down in bed. This stretches and tears blood vessels, compounding injury. Friction, meanwhile, damages the outer skin layer, making it more vulnerable. Moisture from sweat, urine, or feces weakens skin and increases susceptibility to breakdown 8 9.

Intrinsic Risk Factors

Several patient-specific factors increase risk:

• Immobility: Patients who are bed- or chair-bound due to illness, injury, or surgery are at highest risk 2 6.
• Nutritional Deficiency: Poor intake, especially low protein or albumin levels, impairs the skin’s ability to repair itself 2 6 8.
• Impaired Sensation: Neurological disorders, such as after a stroke or spinal cord injury, reduce the ability to feel pain or pressure, delaying detection 2 6 8.
• Comorbidities: Aging, chronic diseases, and acute illness further reduce tissue resilience 2 4 6 8.

Combined Effects

Pressure sores often result from a combination of these factors rather than a single cause. For example, an elderly, immobile patient with poor nutrition and incontinence is at particularly high risk 2 4 6 8 9.

Treatment of Pressure Sores

Effective treatment of pressure sores requires a comprehensive, multi-faceted approach. Interventions range from conservative wound care to surgical options, tailored to the sore’s stage and patient’s overall condition.

Treatment	Approach/Description	Use/Stage	Source
Pressure Relief	Position changes, special mattresses	All stages, prevention	2 4 10 14
Wound Care	Cleaning, dressings, debridement	All, type-specific	4 10 13 14
Nutrition	Protein, vitamin C, supplementation	Adjunctive, all stages	2 4 11 12 14
Surgery	Flap, graft, sinus excision	Severe, non-healing	2 4 5 14
Infection Control	Antibiotics (if cellulitis)	As needed	4 14

Table 4: Main Treatment Approaches for Pressure Sores

Conservative Management

Pressure Relief and Support Surfaces

• Repositioning: Changing the patient’s position regularly—every two hours—is critical to relieve pressure and prevent further injury 2 4 14.
• Mattresses and Cushions: Specialized air, foam, or bead beds distribute weight and reduce pressure. Foam alternatives and overlays lower sore incidence; air-fluidized beds may speed healing 10.
• Mechanical Prophylaxis: Devices such as cushions and heel protectors are beneficial, especially in high-risk patients 2 10 14.

Wound Care

• Cleaning: Use warm saline for cleansing; antiseptics are generally not beneficial 4.
• Dressings: Polyurethane film for superficial wounds, hydrocolloid or alginate dressings for deeper ulcers, and silastic foam for cavity wounds. However, robust evidence supporting the superiority of one dressing over another is lacking 4 13.
• Debridement: Removal of dead tissue, preferably by scalpel or scissors. Enzymatic agents may help if manual methods are not possible 4 14.

Nutrition and Supplements

• Nutritional Optimization: Adequate protein and caloric intake are vital for wound healing. Supplementing with vitamin C (ascorbic acid) has been shown to accelerate healing significantly 2 4 11 12 14.

Infection Control

• Antibiotics: Only indicated if there is evidence of systemic infection or cellulitis. Metronidazole can be helpful for malodorous sores 4 14.

Surgical Interventions

• Flap and Graft Procedures: For chronic, deep, or non-healing sores, surgical closure using skin grafts or muscle flaps may be necessary. The choice of technique depends on sore type (sinus, ulcer, mixed) and location 2 4 5 14.
• Post-Surgical Care: Ensuring continued pressure relief and optimizing overall health are essential to prevent recurrence 2 4 5.

Adjunctive and Emerging Therapies

• Negative Pressure Therapy: Sometimes used to stimulate healing in complex wounds 14.
• Ultrasound, Laser, and Electrotherapy: Evidence is weak or inconclusive for these modalities, so their routine use is not recommended 10 14.

Preventing Recurrence

A comprehensive approach addressing the underlying causes—mobility, nutrition, medical comorbidities, and social factors—reduces the risk of recurrent sores 2 5 14.

Conclusion

Pressure sores are complex wounds that arise from a combination of physical forces and patient-specific vulnerabilities. Early recognition and intervention are crucial to prevent severe complications. Successful management depends on a comprehensive, team-based approach, integrating prevention, wound care, nutritional support, and, when necessary, surgical intervention.

Key Takeaways:

• Pressure sores present as redness, blisters, or deep ulcers, often over bony prominences 2 3 4.
• Classification is based on depth and tissue involvement, with four main stages and additional clinical types 4 5.
• Causes include sustained pressure, shear, friction, moisture, immobility, poor nutrition, and sensory loss 1 2 6 8 9.
• Treatment includes pressure relief, wound care, nutritional support, infection control, and surgery in severe cases 2 4 5 11 12 13 14.
• Prevention and comprehensive care are vital to minimize recurrence and optimize healing 2 4 5 14.

By staying vigilant and informed, healthcare providers, caregivers, and patients can work together to reduce the burden of pressure sores and improve quality of life for those at risk.