Why does the limb swell after fracture or trauma? After the body suffers trauma, many inflammatory factors will be released systemically or locally, which is the body’s protective response. However, on the one hand, these factors stimulate the nerves to issue pain signals, and due to pain, reflexively cause muscle spasm, resulting in stagnation of veins and lymphatic vessels and impaired reflux, causing their walls to dilate and increase permeability, which leads to intertissue edema; On the other hand, inflammatory factors lead to imbalance of fluid exchange inside and outside the blood vessels, resulting in excessive fluid infiltration into the interstitial space of tissues, which eventually leads to swelling of the limb. Patients with lower extremity fractures lie flat in bed for a long time, and the resistance to venous return in the lower extremity is less than when standing. Over time, the body slowly adapts to this low resistance to reflux. When the fracture heals and the patient resumes standing and walking, it is difficult for the lower extremity vessels to adapt to the high resistance of return flow before the fracture, so there is often a period of lower extremity edema. This is especially true for the ankle, which is farther from the heart. Swelling of the extremities after fracture is mostly fully recovered in three months to six months. What are the dangers of limb swelling If swelling is not eliminated in time, it will affect the blood circulation and nutrient supply of the limb, and eventually affect the repair and healing of trauma. If the serious swelling of the limbs makes the pressure in the tissues close to the arterial blood pressure, it will affect the blood supply and make the limbs ischemic, which will cause serious disability of the limbs. It is evident that timely and proper management of swelling is very important. 4 principles for prevention and treatment of limb swelling in the early stage of trauma 1.Rest: The first thing to do in post-trauma treatment is to rest and limit the activities of the traumatized limb to reduce bleeding, slow down the swelling and pain of the limb and prevent the injury from aggravating. 2.Ice pack: It can effectively reduce the degree of swelling and pain of the limb. When using the ice bag temperature should be maintained at 0 ℃ as far as possible to avoid frostbite or not play the role of ice. Each ice pack 15-30 minutes, can be used repeatedly, until the local pain disappears. 3, pressure bandage: pressure bandage on the affected limb, on the one hand, can make the internal pressure of the injured tissue increase, promote the closure of small blood vessels, reduce bleeding; on the other hand, can reduce exudation, reduce limb swelling. The elastic bandage pressure bandage affected limb has certain skills, must use the “surface” pressure technique, so that the entire affected limb everywhere even pressure, and the appropriate degree of elasticity, too loose to achieve the effect, too tight will affect the blood supply of the limb, do not form a strip, the first use of this technique must ask a specialist to guide. If there is numbness, spasm or pain, it means that the bandage is too tight and should be loosened immediately. 4. Elevate the affected limb: It is an important measure to reduce swelling. If the position of the limb is lower than the heart level, the venous return flow has to overcome the double resistance of circulatory resistance and gravity, which is not conducive to the elimination of swelling. Placing the affected limb above the heart level converts gravity into a dynamic factor, which can promote the elimination of swelling. Prevention and treatment of limb swelling in the middle and late stages of trauma Active training should be actively performed under the guidance of a rehabilitation physician in the middle and late stages of trauma, including muscle training and appropriate joint movement of the traumatized limb. Muscle contraction and limb movement can promote venous and lymphatic return, thus promoting the reduction of swelling. In addition, various physical therapy and massage can also improve blood and lymphatic circulation and promote the elimination of swelling.