Causes and risk factors of pressure ulcers (bedsores)

Pressure sores, also known as pressure ulcers or bed sores, are caused by application of extra pressure over patches of skin.

Pressure sores are commonly seen among the very young or in the elderly who are admitted to the nursing homes and are immobile for prolonged periods of time. (1-5)

Causes of pressure ulcers

This can be caused due to:

• pressure exerted by the weight of the body
• frictional rubbing of the skin and
• shearing forces or sliding of the skin between underlying bony structures and external surfaces

Pressure ulcers occur due to a lack of blood supply, and thus supply of oxygen and nutrients, to a part of the body that is also affected by pressure.

Pressure ulcers do not normally affect healthy persons. Healthy individuals usually move their body and change postures unknowingly in order to prevent prolonged pressure on one part.

What risks lead to pressure ulcers?

Some people are at a heightened risk of getting pressure ulcers. The major risks that lead to pressure sores include:

• stress
• duration of stress
• paralysis or spasticity
• infections
• edema
• moisture
• lack of nerve supply
• poor nutrition

Who has a high risk of pressure ulcers?

The at-risk individuals include (1-5):

• Those with problems of mobility who cannot change position by themselves without help.
• Patients who are paralyzed and those with paralysis due to damaged spinal cord
• Patients who have nerve damage and cannot feel pain over the affected areas. This is common with diabetics. High blood sugar leads to damage to the smaller nerves of the feet and other distal parts. This is called peripheral neuropathy and makes a person prone to develop pressure ulcers.
• Patients who have no control over their bladder or bowels.
• Seriously ill patients or those who have undergone massive or extensive surgery that would require time to heal.
• Patients who have had an earlier pressure ulcer or those who have one other pressure ulcer are likely to develop more
• Malnutrition, nutritional deficiency and dehydration and lack of adequate water raises risk of pressure sores. Those who are obese are also at a heightened risk of pressure sores.
• New born ill infants who do not move much as well as very old individuals are at risk. In the elderly there may be reduced blood blow, damaged nerves, thickened arteries due to high blood sugar or cholesterol and impaired mobility that raises the risk of pressure sores. They also may have a thin and fragile skin that is easily broken open on pressure.
• Major injuries like fracture of hip bone in the elderly.
• Patients with heart failure and other chronic heart diseases that make blood flow sluggish are at risk. Those with kidney disease and anemia are also at risk. Patients with mental illness or Alzheimer’s disease are at risk of bed sores.
• Cleansing with soap and water may raise risk of pressure sores. Those with a darkly pigmented skin, or skin discoloration, oedematous skin or hard and indurated skin are at risk of pressure sores. Skin that is too dry or too wet (from urine or sweat) is at risk of sores.