The parts of the body most at risk of developing pressure ulcers are those that are not covered by a large amount of body fat and are in direct contact with a supporting surface, such as a bed or a wheelchair.

For example, if you are unable to get out of bed, you are at risk of developing pressure ulcers on your:

• shoulders or shoulder blades
• elbows
• back of your head
• rims of your ears
• knees, ankles, heels or toes
• spine
• tail bone (the small bone at the bottom of your spine)

If you are a wheelchair user, you are at risk of developing pressure ulcers on:

• your buttocks
• the back of your arms and legs
• the back of your hip bone

Severity of pressure ulcers

Healthcare professionals use several grading systems to describe the severity of pressure ulcers. The most common is the European Pressure Ulcer Advisory Panel (EPUAP) grading system. The higher the grade, the more severe the injury to the skin and underlying tissue. 

Grade one

A grade one pressure ulcer is the most superficial type of ulcer. The affected area of skin appears discoloured – it is red in white people, and purple or blue in people with darker-coloured skin. Grade one pressure ulcers do not turn white when pressure is placed on them. The skin remains intact, but it may hurt or itch. It may also feel either warm and spongy, or hard.

Grade two

In grade two pressure ulcers, some of the outer surface of the skin (the epidermis) or the deeper layer of skin (the dermis) is damaged, leading to skin loss. The ulcer looks like an open wound or a blister.

Grade three

In grade three pressure ulcers, skin loss occurs throughout the entire thickness of the skin. The underlying tissue is also damaged, although the underlying muscle and bone are not. The ulcer appears as a deep, cavity-like wound.

Grade four

A grade four pressure ulcer is the most severe type of pressure ulcer. The skin is severely damaged and the surrounding tissue begins to die (tissue necrosis). The underlying muscles or bone may also be damaged.

People with grade four pressure ulcers have a high risk of developing a life-threatening infection.