A pressure ulcer is an area of skin and tissue damaged by prolonged pressure that cuts off oxygen and nutrients. Depriving oxygen and nutrients from specific areas can cause the death of skin and, eventually, the underlying tissues.

Not all ulcers are pressure ulcers. An ulcer is any open sore or break in the skin that extends beyond the top layer of skin (epidermis) and is accompanied by the sloughing off of dead tissue. Friction or trauma may also result in ulcers by wearing away or cutting past the skin.

Patients who have limited mobility, such as those confined to wheelchairs, and are confined to bed for long periods of time are at risk of developing pressure ulcers. Although pressure ulcers can occur in anyone with limited mobility, paralyzed and comatose people are at higher risk because they are unable to shift and move, which relieves the pressure and restores circulation. People with certain medical conditions, such as diabetes, are also more likely to develop pressure ulcers.

Pressure ulcers are usually painful and may be itchy. They are easily infected, resulting in thick pus, a foul odor, warmth, redness and swelling around the sore. The infection may spread to the underlying muscle and even the bone, leading to serious medical problems.

Pressure ulcers are generally treated by keeping sores clean, covered and free of dead tissue. When infection occurs, antibiotics are used. Severe pressure ulcers, however, may require surgical treatment.