A pressure sore is an impaired blood circulation caused by prolonged pressure on local tissues in the body, resulting in soft tissue ulceration and necrosis due to persistent local ischemia and hypoxia. Pressure sores not only occur in bed-ridden elderly people, but also in elderly people who sit for long periods of time. The risk factors are mainly the following: 1. People who are confused or vegetative need to semi-turn over because they are bedridden for a long time, and may sometimes turn over more slowly; because vegetative and confused patients cannot actively turn over, the local skin is under long-term pressure and blood circulation is impaired, which can cause tissue necrosis to form pressure sores; 2. Patients with stroke, spinal cord injury, or limb paralysis, although they are lucid, have unfavorable activities and remain in 3. Patients with advanced cancer have a very poor nutritional status, reduced skin elasticity and poor blood flow, which can easily lead to pressure sores; 4. 6. Uncontrollable stool or urine, or large amounts of sweating that do not keep the local skin dry, resulting in skin ulceration and pressure sores; 7. Diabetic patients have peripheral vascular and peripheral neuropathy, which is one of the risk factors for pressure sores; 8. Malnutrition; 9. Cardiovascular diseases, such as heart failure; 10. After external fixation of fractures, traction, plaster or splint placement, etc. easily cause pressure sores.