This study mainly focused on the effect of early antiviral treatment on the duration of cough in influenza patients.investigators conducted an early investigation of patients with positive influenza virus and asked whether patients used antiviral drugs in the early stages. According to the use of drugs, patients were divided into oral oseltamivir group, oral lotus phlegm group and other groups, and investigators will collected Inspection information and medication status,during the treatment period of patients.

Cough is a common symptom of respiratory diseases and helps to clear respiratory secretions and harmful factors, but frequent severe coughing has a serious impact on the patient's work, life and social activities. Upper respiratory tract viral infection is a common cause of coughing. Many patients have a long duration of cough after suffering from flu. Cough can last for several weeks, and most often have irritating dry cough or a small amount of white mucus sputum. This type of cough is also often referred to as "subacute cough" or "post-infection cough." The mechanisms that cause this cough have not been fully elucidated, and the effect of conventional treatment is not good, and chest imaging has no obvious abnormalities. The use of large amounts of antibiotics is ineffective or ineffective. Antihistamine H1 receptor antagonists and central antitussives are often only effective or ineffective in the short term. The effects of various bronchodilators and even hormone drugs are not clear. Due to the poor efficacy of multiple treatments, patients are repeatedly subjected to various tests, which not only increases the pain but also aggravates the economic burden.

Therefore, it is necessary to further clarify the causes and treatment measures of post-influenza cough patients.

Inclusion Criteria:

For patients with flu-free flu, cough for at least one week.

1. In line with the flu etiological diagnostic criteria: According to the guidelines set by the National Health and Health Committee, the diagnosis is based on etiological screening methods or confirmed methods; ages 18 to 70 years.
2. There are no influenza complications such as acute lower respiratory tract infection, tonsillitis, sinusitis, otitis media, myocarditis, etc.
3. It is usually healthy and there are no chronic underlying diseases such as hypertension and diabetes.
4. Treating with cough as the main symptom, the cough lasts for at least one week and the chest radiograph is normal.
5. Signed informed consent.

Exclusion Criteria:

1. Suspected flu patients who have not received the flu etiology test;
2. There is a clear comorbid disease (combined with other sites of acute bacterial or viral infections);
3. There is a clear cough caused by other reasons;
4. With severe liver and kidney dysfunction;
5. Pregnant women.

Flu patients who were diagnosed in our hospital from April 2018 to July 2019