Recently, many netizens reported that after infection with COVID-19, even though nucleic acid and antigen showed negative, the symptoms of cough still did not disappear, and some were even more serious. How long will the cough symptoms generally last after COVID-19 infection turns negative? What are the possible causes of cough after turning yin? What countermeasures should be taken? In this regard, Niu Hongtao, a doctor from the Department of Respiratory and Critical Care Medicine of China Japan Friendship Hospital, was interviewed by the reporter of Science and Technology Daily. Cough usually recovers in two weeks after infection, and may last for up to eight weeks. "The respiratory tract infection above the Omicron virus strain is mainly caused by secondary tracheitis and bronchitis, which causes cough. At the same time, the virus causes damage to the respiratory mucosa, and immune cells gather here to 'participate in the fight'. After completing the task, the throat, trachea and bronchial secretions are expelled from the body through cough and expectoration, and the battlefield is cleared." Niu Hongtao said. The process of clearing up the battlefield takes a certain time. The cough of patients with mild illness may continue after the fever subsides, and they usually recover within two weeks after the onset. "However, as long as airway inflammation persists, cough may last up to 8 weeks after infection," Niu Hongtao told Science and Technology Daily. According to Niu Hongtao, cough can be divided into dry and wet types. Most of the viral infections are the former, with no sputum. However, some patients may cough with white sticky sputum or with sputum that is difficult to cough up, leading to the persistence of cough. "Cough is a protective mechanism of the human body. Cough after infection is a common occurrence of many respiratory virus infections, so don't be too nervous." Niu Hongtao stressed that, "It is recommended to drink more water, rest more, talk less, improve the temperature and humidity of the airway (apply a damp, hot towel on your face to absorb steam), and promote the discharge of sputum after turning negative." If the cough lasts for more than 3 weeks or the symptoms become worse, you should see a doctor in time. What measures can be taken to deal with the cough? Niu Hongtao introduced that drinking honey water or soup boiled with loquat paste, pears, etc., and humidifying the environment are conducive to relieving cough. "If you want to cough, but there is no water around you, you can try to swallow it repeatedly." In addition to the above non drug methods, you can also take antitussive drugs to relieve your cough. "Everyone's basic physical conditions are different, and their reactions to drugs are also different. If their cough affects their life and sleep, it is recommended to go to the respiratory department of the hospital for medical treatment or online consultation in a timely manner to obtain personalized treatment suggestions. At the same time, they should avoid smoking and stay away from the polluted and pungent smell environment." Niu Hongtao said. Some people cough up sputum and are difficult to cough up. In this regard, Niu Hongtao suggested taking expectorants. "If the color of sputum changes from white to yellow, and the amount is increasing, even purulent sputum, it may be due to the decline of respiratory defense ability caused by viral infection, combined with bacterial infection, and it is recommended to take antibiotics for treatment for 3 to 5 days." Niu Hongtao added that if there is hemoptysis (blood in sputum), cough at night (or when changing posture) becomes worse, cough a lot of yellow purulent sputum, fever again, shortness of breath, dyspnea If the original symptoms such as chest pain are obviously aggravated, and the lower limb edema or cough exceeds 3 weeks, it is recommended to go to the hospital. (Outlook New Times)