Characteristics of unhealthy behaviors affecting health: 1) The incubation period is long. After the unhealthy lifestyle is formed, it usually takes a long time to have an impact on health and produce obvious pathogenic effects; 2) The specificity is poor, and there is no clear correspondence between unhealthy lifestyle and diseases, that is, one behavior may be related to many health problems, and one disease may also be related to many behaviors; 3) There is a strong synergy and a variety of bad behaviors exist at the same time. The effects of various factors on the body are not simply additive, but mutually reinforcing. The harm caused by this synergy will eventually be greater than the sum of the individual effects of each factor. The combined effect of unhealthy lifestyle and many factors can greatly increase its pathogenic effect.