Pressure Ulcers

What is a Pressure ulcer?

A pressure ulcer is an injury to the skin that occurs when a patient lies or sits too long in the same position. Pressure keeps blood from getting to the tissue, causing cells to die and the skin to break down. As the tissue dies, an open sore forms, and this can even be painful or become infected. In severe cases, the muscle, tendon, or bone may begin to show. Pressure ulcers usually occur on bony areas of the body, such as the tailbone, back, buttocks, back of the head, elbows, heels, hips, and shoulders.  Some patients get them on their ears.  If you spot them early, you may be able to stop them from forming or prevent them from getting worse.

How do people get pressure ulcers?

Patients who are unable to get out of bed or spend most of the day in a wheelchair are at high risk of getting a pressure ulcer. People who cannot move certain parts of their bodies are also at risk (e.g., a person who has difficulty moving his/her leg after a stroke). Older people are at risk because their skin is thin and fragile. People with certain medical problems are also at risk.  These problems include:

  • diseases that affect the flow of blood in the body, such as diabetes or heart disease
  • kidney disease and anemia (lack of iron in the blood)
  • swelling or infection
  • mental illness or Alzheimer’s disease
  • low body weight, dehydration, and poor diet
  • skin that is too dry or too wet (from urine or sweat)
What are the stages of pressure ulcers?

The doctor or nurse can tell how bad the problem is by looking at the skin and measuring the sore.  Each pressure ulcer is graded (called staging) based on the amount of breakdown to the skin.

Normal Skin:
The skin is made up of two layers: the epidermis and the dermis. The epidermis is the thin, tough outer layer.  This layer has no blood vessels and renews itself about every month. The dermis is the thick, inner layer that attaches to the tissue that is beneath it.  The dermis gives the skin strength and flexibility.  The dermis contains blood vessels, hair follicles, oil glands, sweat glands, as well as nerve endings.  Underneath the dermis, are fatty tissue, muscle, blood vessels, nerves, and bone.


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Category or Stage I:
In people with lighter skin tones, the area over a bony body part may look red. When you press the area with your fingers, the skin does not turn white.

In people with darker skin tones, this area may look red, blue, or purple.

The area may be painful and feel warmer or cooler than the skin around it.  At this point, the skin is not broken.


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Category or Stage II:
The outer layer of skin will blister or form a shallow, open sore.


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Category or Stage III:
The area below the skin, including the nerves, gets damaged, and the sore looks like a crater.  Fat may be visible, but bone and muscle cannot be seen.


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Category or Stage IV:
This is a deep wound, and you can see muscles, tendons, or bone.


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Unstageable/Unclassified:
The top layer of the sore is covered by dead tissue, which may have a yellow, tan, gray, green, or brown color.  It may also look like a scab.  The dead tissue or scab covers a deeper, more serious wound and needs to be removed by a doctor or wound specialist.


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Possible Deep Tissue Injury
A deep tissue injury, not to be confused with a Stage I pressure ulcer, is a purple or maroon area of damaged tissue under intact skin; it looks like a deep bruise. 

A suspected deep tissue injury needs to be examined by a doctor or wound specialist as it can quickly become a Stage III or IV pressure ulcer.


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Illustrations presented with permission from the NPUAP.

What if I find a new pressure ulcer?

Pressure ulcers are very hard to treat and can be painful.  They can cause infections that may require a hospital stay.  So work closely with the doctor or nurse to make sure that everything is being done to heal ulcers when they show up and to stop more ulcers from forming.

Follow the steps to prevent new ulcers (see "How do you prevent pressure ulcers?").  In addition, the doctor or nurse may suggest that you speak with a registered dietitian to make sure that the patient follows a good diet and drinks enough fluids.  The doctor or nurse will also monitor the ulcer and may a follow up with a wound care surgeon.