After influenza virus invades the human body, it can form immune complexes and cause glomerular lesions; it can react with antibodies to activate complement, leading to glomerular cell damage; it can also directly attack the glomerular endothelial and epithelial cells and damage the glomeruli. Through the above action process, it causes nephritis to occur. 1. Formation of immune complexes: after human infection with influenza virus, antibody recognizes viral surface antigen and forms immune complexes deposited in the glomerulus with blood flow, activating monocytes and phagocytes and causing glomerular lesions; viral antigen is first deposited in the glomerulus, antibody reacts directly with antigen and combines with complement, and neutrophils infiltrate locally, resulting in glomerular injury. 2. Activation of complement: when patients who already have nephritis are infected with influenza virus, viral antigen reacts with antibody to activate complement, which produces chemokines such as Ca5, causing infiltration of neutrophils and monocytes, and releasing metabolites such as protease and oxygen free radicals, which cause damage to glomerulocytes and the basement membrane, and exacerbate the severity of nephritis. 3. Direct attack: the gene of influenza virus is prone to mutation, resulting in the change of its surface antigen, the new antigen can not be recognized by the body’s immune system, the virus involves the glomerular epithelial cells and produces damage, resulting in a decrease in the glomerular filtration rate, and hypertension, pulmonary edema and renal insufficiency may occur in the long term. It leads to poor prognosis of nephritis. So nephritis patients need to actively prevent infection and go to regular hospitals for regular treatment in time to avoid aggravation of the condition.