Pressure Ulcer: Definition, Stages & Treatment

Instructor: Danielle Haak

Danielle has a PhD in Natural Resource Sciences and a MSc in Biological Sciences

What is a pressure ulcer? You may have heard them referred to as bedsores, since they happen when pressure on parts of the body causes sores to develop. Read this lesson to learn about how they're classified and treated.

What is a Pressure Ulcer?

Let us begin by defining ulcers: An ulcer is an open wound that doesn't heal and can be found both outside and inside the body. A pressure ulcer, then, is a section of skin that becomes a wound due to pressure being been placed on the area. It is also known as a bedsore or pressure sore. Pressure ulcers most often occur on 'pressure points' on bony parts of the body with little fat, such as the elbows, hips, heels, ankles, shoulders, buttocks, or back of the head.

People with limited mobility are at high risk of developing pressure ulcers.

Causes of Pressure Ulcers

Pressure ulcers are caused by pressure on the body that disrupts blood flow to the tissues. When blood flow is disrupted, tissues don't receive adequate oxygen and nutrients, causing them to die. There are different types of pressure that can lead to pressure ulcers:

  • Interface pressure: The body presses an area of skin onto a hard surface.
  • Shear: The layers of skin slide over deeper tissues, causing irritation.
  • Friction: An external object rubs against the skin's surface.

Pressure ulcers most commonly form in older people with limited mobility, especially those with fragile skin. As you age, your skin becomes thinner, less elastic, and more prone to injuries. They may also be caused by diseases that disrupt blood flow, such as diabetes or multiple sclerosis, and they may be more common in people who have injuries that restrict movement. Other causes include urinary or bowel incontinence, malnourishment, or prolonged moisture on the skin.

Pressure Ulcer Symptoms

Pressure ulcers start as reddened areas on the skin that get worse over time. They can be painful or itchy when they first develop, and they may initially appear like blisters that eventually develop into open wounds. The ulcer itself may be firm or mushy, and it might be warmer or colder than the surrounding tissue.

In general, pressure ulcers can be categorized based on the severity of the ulcer.

  1. Stage 1: A superficial red patch develops that doesn't turn white when pressed; this is indicative of a pressure ulcer forming.
  2. Stage 2: The skin blisters or an open wound forms; the surrounding area may be red and painful.
  3. Stage 3: The sore sinks in like a crater or cavity, indicating that the tissue below the skin is also damaged.
  4. Stage 4: The ulcer is so deep that it may damage the underlying muscle, bone, tendons, or joints; at this stage tissue necrosis happens and the person is at serious risk of a major infection.

If an infection occurs, the tell-tale signs include a bad smell, the presence of pus, redness, pain, and swelling. If the infection spreads, it can cause fever, weakness, or confusion and can be life-threatening.

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