A pressure sore (bed sore) is an injury to the skin caused by constant pressure. This often occurs when a person lies in bed or sits in a wheelchair for a long time. Pressure sores usually form over bony areas such as the hips, lower back, elbows, and heels. To prevent pressure sores, you need to change positions often.
Severe pressure sores are hard to treat and slow to heal. If they don't heal, they can lead to skin, blood, or bone infections.