Why is it so hard to treat pressure sores?

Lack of education: Pressure sores aren't hard to treat, but people can suffer for years with them because the true cause of the problem isn't addressed. If pressure & shear (sliding) are removed and appropriate wound dressings are in place, it should heal easily. If a pressure sore is not healing it's because there's still pressure on that area, even if the person is on a special "pressure support" surface.

Other related issues: Pressure ulcers are indeed a direct result of unrelieved pressure to the skin. While pressure relief is important, malnutrition causing low blood proteins, chronic urine or fecal incontinence and underlying bone infection can all cause non-healing of the ulcer. If an ulcer has not improved within 3 weeks of appropriate pressure relief seating and mattresses, then blood tests and xrays are needed.

Constant pressures: Pressure sores are hard to treat because of the constant pressure on the skin when patients are non-ambulatory and bruise the skin, prome to cutaneous bacterial infections. Non-ambulation can also cause rhabdomyolysis.