Influenza B is usually mild and the symptoms can be relieved in 3~5 days, if complications occur, the cure time will be prolonged. Influenza B is known as influenza B virus cold, is a self-limiting disease, the general incubation period of the virus is 2~4 days, common in the age of 5 years and over 65 years old people, usually through coughing, sneezing and other droplet transmission. Clinical manifestations commonly include fever, headache, generalized discomfort, and may be accompanied by loss of appetite, depression, and muscle aches and pains. Influenza B common symptoms are fever, abdominal pain, vomiting, diarrhea, no complications in the onset of the majority of 3 to 5 days after the body temperature returns to normal, the systemic symptoms are gradually relieved, but the cough and physical recovery still need a period of time. Treatment can use oseltamivir,, paramivir antiviral and so on. If there are comorbidities such as pneumonia, myositis, myocarditis, etc., symptomatic treatment is needed. If the body temperature remains unstable for three days and there are signs of lethargy and fast breathing, it is recommended to consult a doctor in time to treat the complications to avoid serious consequences.