Pressure Injury 101: The 4 Stages

Here are the four stages of a pressure injury, from onset to severe injury.


Pressure injuries—also known as bedsores, pressure sores and decubitus ulcers—are a significant issue in healthcare settings. In the United States alone, 2.5 million people develop pressure sores annually, with 60,000 of those cases being fatal. 

Treating pressure sores after they develop can become labor-intensive and quite costly for health institutions, while also causing undue suffering for patients. By placing a larger emphasis on injury prevention from the outset of a hospital stay, we can reduce the incidence of pressure sores and ultimately divert valuable medical personnel to more urgent priorities.

And of course—paying close attention to pressure injury development also serves to elevate patient care and outcomes. The key here is ensuring that every member of your healthcare team is properly trained on prevention, and that begins with recognizing pressure sores for what they are: dangerous, yet preventable, injuries.

Here are the four stages of a pressure injury, and how to treat them effectively.


How do pressure sores begin?

Pressure sores develop for many reasons, so hospitals should have strategies in place to screen for risks among all of their patients. However, there are certain environments that lend themselves particularly to pressure injury development, including moisture, shear, advanced age, limited mobility and lack of access to monitoring technology. It’s important to be vigilant with proactive screening for bedsore development, especially with high-risk patients. 

Here are the early warning signs of a pressure sore:

  • Discoloration or dark skin, whether redder, bluer or more purple than usual
  • An area of skin feeling warmer to the touch than surrounding skin
  • Skin that feels firmer in one spot than usual
  • Itchy, painful skin
  • When the skin is pressed down on, it doesn’t appear lighter
  • Swelling on the skin


Stage1-Darkly Pigmented SkinIdentifying a stage one pressure injury

Early on in pressure ulcer development, the skin is developing injury. While no open sores or broken skin are present yet, the skin may appear redder, warmer or firmer than usual. Known as a non-blanchable erythema of intact skin, the color change may indicate the beginnings of a serious injury to the deep tissue.

Stage 1 L Pigment

Watch for these signs when monitoring for a stage one pressure


  • The skin is discolored: it may be redder or even bluer than is typical. (In more dark-skinned patients, the skin may turn purple.)
  • The skin feels warmer to the touch.
  • The skin feels firmer or softer in one spot than usual.
  • The skin is itchy and painful.
  • When the skin is pressed down on, it doesn’t appear lighter or turn white to the touch.
  • The skin is swelling or beginning to show signs of a blood-filled blister.


Treating a stage one pressure injury

Once a stage one injury has been diagnosed, there are several immediate actions that can stop it from progressing to an open wound—or decubitus ulcer—which demands urgent wound care. Treating an existing injury requires the immediate reduction of pressure on the area of affected skin. This is achieved by turning the patient and/or using a specific mattress topper or material that helps the patient’s skin. 

The most important thing to understand is that stage one pressure ulcers require immediate response, as they can become increasingly difficult to treat should they move into stage two. And since stage one ulcers do cause tissue damage, health care professionals must also implement treatment plans for quick healing.


Stage2-Darkly Pigmented SkinIdentifying a stage two pressure injury

In a stage two ulcer, a break in the skin occurs, often including an open sore. Stage two can be very painful, creating serious damage within the skin. Known as partial-thickness skin loss with exposed dermis, these bed wounds can quickly become something worse and may present as a blood-filled blister.

Watch for these signs when monitoring for a stage two pressure injury:Stage 2 L April 2020

  • The skin is itchy and painful, and may feel warmer to the touch.
  • The sore is oozing clear liquid, pus or blood.
  • The skin has developed an open wound.
  • The skin isn’t covered by slough yet, but is showing signs of erosion or blistering up.


How to treat a stage two pressure injury

By treating a stage two pressure injury with urgency, you may be able avoid deeper tissue damage or infection. It’s vital to implement wound care strategies right away, taking steps such as removing pressure from the affected areas of the skin, turning the patient regularly and integrating technology that helps the skin.

Because stage two pressure injuries can advance to stage three quickly, immediate action by health care staff is required to prevent further tissue damage and infection.


Stage3-Darkly Pigmented SkinIdentifying a stage three pressure injury

In stage three, the pressure injury has developed into the soft tissue underneath the skin. Known as full-thickness skin loss, this stage may show a deep wound, especially in an area with more adipose tissue.

Stage three injuries may begin extending down into the tissue, showing exposed fat. At this stage, the injury may not even cause pain to the patient, indicating possible deep tissue damage.

Watch for these signs when monitoring for a stage three pressure ulcer:Stage 3 L April 2020

  • The skin has developed a crater, and might even include visible adipose tissue.
  • The sore has a foul odor.
  • The sore is oozing clear liquid, pus or blood.
  • The sore may be covered by slough, but not in a way that destroys tissue visibility.


How to treat a stage three pressure injury

Wound care strategies must be implemented quickly, particularly if any signs of infection are already present. The goal is preventing the ulcer from progressing to stage four. Staff should implement turning and pressure-relieving strategies to take additional pressure off of the wound, while remembering that when treating one pressure sore, they can’t give a new one opportunity to develop.

Every hospital or health care institution has wound care strategies included in their protocols, and these should be followed with urgency. Irrigate and properly dress the wound, and prescribe antibiotics if required.


Stage4-Darkly Pigmented SkinIdentifying a stage four pressure injury

By the final and most serious stage of a pressure sore, the skin may have receded into the muscle and bone, causing lasting damage to the skin and underlying areas. Known as full-thickness skin and tissue loss, this stage can involve visible or palpable fascia, tendon, muscle and bone, and even dead tissue.Stage 4 L April 2020

In a stage four pressure injury, you’ll see a marked difference from earlier stages. Stage four injuries are incredibly serious, and may show visible deep tissue damage, drainage, pus and a wound covered with a thin layer of eschar. These often become infected, and may require surgery to repair. 

Watch for these signs when monitoring for a stage four pressure ulcer:

  • The skin has developed a crater, and the wound bed may include visible adipose tissue, muscle or bone.
  • The sore has a foul odor.
  • The sore is oozing clear liquid, pus or blood, or showing other signs of infection.
  • The sore may show skin that has turned black with dead tissue.
  • The sore is large, deep and noticeable and may be covered by slough or eschar.


How to treat a stage four pressure injury

Stage four pressure ulcers require immediate wound care strategies, and can necessitate both surgery and serious antibiotics. Stage four bedsores are dangerous, and should be treated as such. Irrigating and properly dressing the wound is essential, and antibiotics may be needed. Stage four pressure injuries may also require surgery, and the consideration of a pressure ulcer advisory panel.


Technology to prevent pressure injuriestechnology-to-prevent-pressure-sores

Integrating sensing technology into your institution’s pressure injury treatment and prevention strategies can significantly improve both patient outcomes and hospital operations, reducing staff workloads and increasing efficiency.   

XSENSOR offers technology for dynamic sensing and continuous pressure monitoring, giving medical professionals accurate, real-time data to inform individualized treatment—and, ideally, the complete prevention—of pressure injuries.

XSENSOR’s ForeSite technology is specifically designed to help clinicians alleviate and prevent the formation and progression of pressure sores, helping you address three main culprits: surgical tables, hospital beds and wheelchairs.

  • For hospital beds: Our unique ForeSite Intelligent Surface mattress system uses more than 1500 sensor cells on the surface of a mattress or fitted cover to measure patient body surface pressures, displaying data in real time for continuous monitoring. The system includes a turn clock to track repositioning and informs better patient care.
  • For surgical tables: Our ForeSite OR system carries the same technology through to the operating room, which is excellent for managing risk in longer surgeries.
  • For wheelchairs: Our ForeSite SS system utilizes advanced sensing for seating assessment of those in wheelchairs.

At XSENSOR, we support health professionals in providing high quality patient care through intelligent dynamic sensing technology. Contact us today, and we’ll elevate your standard of care together.

Ultimate Guide To Preventing Pressure Injuries in the Hospital


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