Decubitus ulcers are lesions of the skin and the underlying tissue caused a combination of several factors. Possible causes are pressure, friction, humidity, shearing forces, temperature, age, continence, and medication. They most often occur over bony or cartilaginous areas such as sacrum, elbows, knees, and ankles.
Decubital ulcer can be prevented by avoiding pressure on sensitive tissue, for example by padding, mechanical devices to mimic the effect of movement, such as alternating pressure mattresses or simply regular nursing intervention. Often a 'turning schedule' is employed to ensure the weight of the immobile patient is redistributed, reducing sustained pressure on a vulnerable area. Dehydrated people are more at risk. Also, urinary or fecal incontinence can cause skin damage and thus lead to decubitus ulcers.