(HealthDay News) -- Pressure ulcers, commonly called bed sores, are wounds that develop on the skin from staying in one position without shifting your weight.

People who have just had surgery and aren't able to get out of bed, for example, may acquire a pressure ulcer because the constant weight on the affected area decreases blood supply, killing affected tissue.

The U.S. National Library of Medicine says the following conditions may foster pressure ulcers.:

• Being unable to get out of bed, or being confined to a wheelchair.
• Developing skin wounds easily, or having a chronic condition that affects blood circulation.
• Being unable to move parts of the body without assistance due to injury or illness.
• Being malnourished.
• Being mentally impaired or having dementia.
• Being older or incontinent.