1, secondary bacterial upper whistle infection such as acute sinusitis or purulent tonsillitis. 2, secondary bacterial pneumonia Influenza patients may occur as follows three kinds of pneumonia, namely, in addition to primary influenza viral pneumonia, but also secondary bacterial pneumonia, or mixed viral and bacterial infectious pneumonia, influenza virus infection leads to epithelial cell necrosis of the whistle tract, cilia shedding and mucus secretion dysfunction, local defense function is reduced, prone to secondary bacterial infection, manifested as acute bronchitis and pneumonia, common type Influenza secondary bacterial pneumonia is more common than influenza viral pneumonia, mostly caused by Streptococcus pneumoniae, Staphylococcus aureus, Haemophilus influenzae, etc. Secondary bacterial pneumonia can often be distinguished from primary viral pneumonia by clinical features, secondary bacterial pneumonia mostly occurs after the influenza condition has improved, followed by a resurgence of temperature, with signs and symptoms of bacterial pneumonia; bacterial pneumonia can also coexist with Bacterial pneumonia can also coexist with viral influenza pneumonia. Patients are usually elderly or have chronic cardiopulmonary, metabolic or other diseases, and usually start with simple influenza, which worsens after 2 to 3 days, with higher temperature, chills, general toxic symptoms, increased cough, pus sputum, chest pain, inspiratory distress, cyanosis, and up sounds in the lungs. Pleurisy, pleural effusion or abscess chest, leukocyte count and neutrophil ratio significantly increased, gram stain of sputum smear and sputum culture can show the relevant pathogenic bacteria, serious cases can cause post-influenza toxic shock syndrome. Reye syndrome (encephalopathy – hepatic steatosis syndrome) is a hepatic, neurological complication of influenza A or B virus infection, in the acute whistle infection a few days after the fever subsides nausea, frequent vomiting, drowsiness, coma and convulsions and other neurological symptoms, large liver, no jaundice, mild impairment of liver function, histological changes characterized by hepatic, renal and cardiac steatosis, Reye syndrome etiology is unknown. The cause of Reye’s syndrome is unknown, but in recent years it is thought that it may be related to the long-term use of aspirin. 4, other complications A small number of patients may develop myositis, more common in children than adults, manifested as pain and pressure pain in the gastrocnemius and flounder muscles, can occur lower limb convulsions, severe cases can not walk, influenza B virus is more prone to this complication than type A, serum creatine phosphokinase levels transiently elevated, the patient recovered completely after 3-4 days, there are reports that a very small number of patients can develop myoglobinuria and renal failure, there are also Myocardial damage has been reported, manifested by abnormalities in the electrocardiogram, arrhythmias, and increased levels of cardiac enzymes, while pericarditis has been rarely reported.