Pressure injuries are caused by constant pressure on the skin. They often form on skin that covers bony areas. Common sites include the back of the head and ears, the shoulders, the elbows, the lower back and buttocks, the sit bones, the hips, the inner knees, and the heels.

Pressure injuries may also form in places where the skin folds over itself. And they can occur where medical equipment puts pressure on the skin. For example, they may form where oxygen tubing presses on the ears or cheeks.