Local soft tissue infiltration is the slow infiltration of fluid into soft tissue, the infiltration of abnormal cells into human tissue or the appearance of body cells that should not be present under normal circumstances, and the expansion of certain diseased tissue into the surrounding area. The appearance of abnormal substances or excessive accumulation of certain pre-existing substances within the cells or in the interstitium is also called infiltration. Some degeneration or deposition is also called infiltration. So, what are the causes of local soft tissue infiltration in patients? The following is a brief introduction: infiltration is mostly pathological, when the inflammatory cells infiltrate the inflamed tissue, which is the expression of the body’s defense function against injury. The body defense (body defense) refers to the body’s inherent resistance to internal and external pathogenic factors invasion function. The body is often under the threat of various pathogenic factors, as well as the damage caused by the body’s own immune response, which may cause damage to the body. At the same time, the organism itself has a complete defense system to protect the organism from the damage caused by pathogenic factors. When the body’s defense function is disrupted, disease occurs. After the disease occurs, the body’s defense function can try to eliminate the disease-causing factors, reduce the damage, make the lesion heal, and restore the function of the damaged tissue as much as possible. However, sometimes the result of healing can lead to new damage and dysfunction, for example, hepatic sclerosis can occur after healing of liver tissue in hepatitis B.