First, there are confirmed patients or close contacts in your area, and the community is classified as a red area. Second, it has had close contact with confirmed patients or asymptomatic infected people. Third, some of the people you contact have had close contact with confirmed patients or asymptomatic infected people. After the health code turns red, our travel will be restricted. If you want to change it back, you can stay in the risk-free area for 14 days and report the formation of the day on time every day. So the red health code can be changed back.