How and where do pressure ulcers occur?

How do pressure ulcers occur?

Ischemia has previously been widely recognized as the cause of pressure ulcers and has historically been explained as the sole reason for their development. However, recent research has shown that there is another primary cause of pressure ulcers – cell deformation. Cell deformation typically involves higher and more intense pressure, while ischemia involves lower pressure that lasts for a longer period of time.(1)

(2) Kosiak (1959), (3) Witowski & Parish (1982).

(4) Leopold & Gefen (2013), (5) Gefen et al. (2022).

Coastline rocks

The conflict

What these factors have in common is that both lead to cell death. The significant difference between ischemia and cell deformation is that cell deformation can pose an immediate risk to the patient. This is because pressure ulcers resulting from cell deformation can develop within just a few minutes.(1)(5)

How can we determine whether we are dealing with ischemia or cell deformation? The answer is that it is not possible to know for certain, which is why a solution addressing both factors is needed.

How do we address this?


Pressure ulcers can occur on any part of the body. Particularly vulnerable areas for pressure ulcer development include the sacral area (sacrum), ischial tuberosities (sitting bones), the hip area including the area between the greater trochanter and the iliac crest, as well as the heel and malleolus (ankle bone).

Other body parts can also be affected. Pay special attention to pressure over prominent bony prominences and be aware that medical devices can cause pressure ulcers, such as catheters, plaster casts, nasogastric tubes, oxygen masks, or when a person is intubated. When providing care in a supine or lateral position, additional vulnerable areas include the ears, face, knees, and feet.(1)


What factors increase the risk of pressure ulcers?

Research has identified several risk factors for the development of pressure ulcers. When these factors are combined with pressure and shear, the risk of an individual developing pressure ulcers increases. Some known risk factors to consider include advanced age, malnutrition, and elevated body temperature. It is important to note that individuals with impaired mobility and activity, decreased general health status, being bedridden and/or wheelchair-bound, have an increased risk of developing pressure ulcers.(1)

Download our Pressure Ulcer Action Plan to learn more

(1) European Pressure Ulcer Advisory Panel, National Pressure Injury Advisory Panel and Pan Pacific Pressure Injury Alliance. Prevention and Treatment of Pressure Ulcers/Injuries: Clinical Practice Guideline. The international Guideline. Emily Haesler (Ed.). EPUAP/NPIAP/PPPIA: 2019
(2) KOSIAK M. (1959). Etiology and pathology of ischemic ulcers. Archives of physical medicine and rehabilitation, 40(2), 62–69.
Witkowski, J. A., & Parish, L. C. (1982). The decubitus ulcer. International journal of dermatology, 21(5), 259.
(3) Witkowski, J. A., & Parish, L. C. (1982). The decubitus ulcer. International journal of dermatology, 21(5), 259.
(4) Leopold, E., & Gefen, A. (2013). Changes in permeability of the plasma membrane of myoblasts to fluorescent dyes with different molecular masses under sustained uniaxial stretching. Medical engineering & physics, 35(5), 601–607.
(5) Gefen, A., Brienza, D. M., Cuddigan, J., Haesler, E., & Kottner, J. (2022). Our contemporary understanding of the aetiology of pressure ulcers/pressure injuries.  International wound journal, 19(3), 692–704.