Pseudomembrane is the local mucosal epithelial cells, because of various reasons and necrosis, when the local blood vessel expansion and congestion, there will be a large number of leukocytes and cellulose exudation, and the formation of grayish-white membrane on the surface, which is pseudomembrane, pseudomembrane is formed mainly due to the following reasons: 1, when some special bacteria, such as diphtheria bacillus in the throat when the parasitism, pseudomembrane can be formed, and at the same time, it is easy to fall off and cause Respiratory tract obstruction, serious cases can be suffocated to death. 2, when a large number of antibiotics, low resistance in the body, and finally in the intestinal tract to form a pseudomembrane, can be in the defecation of mucous membrane-like shedding, the patient can be ectopic flora and lead to elevated body temperature, and even chills, high fever and other symptoms. 3, there are also some patients because of the special bacterial infections resulting in the endothelial membrane.