At present, the goal of prevention and control of COVID-19 is to protect health and prevent severe cases. How to use medicine scientifically after COVID-19 infection? What are the precautions after rehabilitation? How long can I exercise? For people not infected with COVID-19, will blood donation increase the risk of infection? The joint prevention and control mechanism of the State Council organized authoritative experts in relevant fields to answer the current hot issues of public concern. How to use medicine scientifically after infection? Gao Yan, director of the Infection Department of the People's Hospital of Peking University, said that after infection with COVID-19, there are clinical symptoms such as high fever. When the body temperature exceeds 38.5 degrees Celsius, the human body will feel very uncomfortable. At this time, some antipyretic drugs need to be used. Gao Yan said that if the patient has some chronic diseases, such as gastric ulcer, duodenal ulcer, or some basic diseases of the gastrointestinal tract, he should not take it on an empty stomach when using antipyretic and analgesic drugs. In addition, intensive drug use may induce gastrointestinal bleeding and other symptoms. It may be safer to use some protective agents of gastric mucosa together with antipyretic and analgesic drugs. "For most COVID-19 patients, the main treatment is mild illness, and symptomatic treatment is OK. Antitussive, antitussive, and expectorant drugs are relatively safe." Gao Yan reminded that there may be some interactions between many drugs in clinical practice, especially for people with serious chronic basic diseases, they should use drugs under the guidance of medical institutions and doctors. What should be paid attention to after rehabilitation? Liu Qingquan, president of the Beijing Hospital of Traditional Chinese Medicine affiliated to Capital Medical University, said that seven to ten days after infection with COVID-19, most people will enter the recovery state. Maybe nucleic acids or antigens have turned negative, but there will still be some symptoms left, such as cough, throat discomfort, etc. In the rehabilitation period, the patients should maintain high morale. Liu Qingquan reminded us not to overeat after recovery, but to maintain a light diet, strengthen nutrition, take in enough protein, eat more vegetables and fruits, and ensure the recovery of physical strength. At the same time, the pace of life and work should be appropriately slowed down, and do not stay up late. For some people who have returned to work after rehabilitation, Gao Yan said that they can return to work if their physical strength has improved significantly after the fever has subsided. However, some respiratory symptoms may recover slowly, and you should stay in bed more during the fever period. How long can I exercise after recovery? Liu Qingquan reminded that moderate exercise is conducive to recovery, but not strenuous exercise. Excessive exercise can not restore health, and there may be some other problems. Liu Qingquan said that you can choose an appropriate amount of exercise according to your own exercise habits, not more than one-third of the usual amount of exercise, and gradually increase it. Gao Yan said that for young and middle-aged people, the process of entering the recovery period will be shorter, which will not affect the resumption of work and production. However, the high-intensity fitness exercise should take a little slow, pay attention to rest, strengthen nutrition, and let yourself return to normal as soon as possible. "For the elderly over 60 years old, especially those with chronic diseases such as diabetes, hypertension, coronary heart disease, we should focus on the respiratory symptoms, such as whether cough, chest tightness, shortness of breath and other symptoms are aggravated." Gao Yan said that these respiratory symptoms may continue after nucleic acid or antigen turns negative about a week, etc