Primary prevention, also called etiological prevention, is to prevent the occurrence of diseases by taking measures to eliminate the influence of pathogenic factors on the harm of the body or improve the resistance of the body. In primary prevention, if preventive measures are taken before the pathogenic factors of diseases enter the environment, it is called fundamental prevention. For example, in order to protect people's health, from the national perspective, a series of laws or regulations have been promulgated in the form of decrees to prevent harmful factors from entering the national living environment.
The first level of prevention includes measures for individuals and measures for the whole public. The measures for healthy individuals are: ① personal health education, paying attention to reasonable nutrition and physical exercise, and cultivating good behavior and lifestyle; ② Organize vaccination to improve people's immunity and prevent diseases; ③ Do a good job of premarital examination, prohibit consanguineous marriage and prevent genetic diseases; ④ Do a good job in health care during pregnancy and childhood; ⑤ Some individuals with high risk of diseases take drugs to prevent the occurrence of diseases, that is, chemical prevention. Social and environmental measures taken for public health, such as formulating and implementing various health-related laws and regulations, public health friendly policies, conducting public health education through various media, preventing pathogenic factors from endangering public health, and improving public health awareness and self-control ability. Such as the provision of clean and safe drinking water, environmental protection measures for the atmosphere, soil and water sources, food safety, the construction of public sports venues, and the prohibition of smoking in public places.
Secondary prevention is the "three early" prevention work of early detection, early diagnosis and early treatment in the early clinical stage of the disease to control the development and deterioration of the disease. For example, cervical cancer takes more than ten years to develop from in situ cancer to invasive cancer, usually 5 ~ 8 years. The earlier the diagnosis, the better the prognosis. The specific methods of early detection are mainly general survey, screening and regular health examination. For infectious diseases, in addition to the "three mornings", it is still necessary to report the epidemic situation early and isolate patients early, that is, "five mornings".
Third-level prevention, taking timely and effective treatment measures to prevent the development of the disease, prevent the deterioration of the disease, and prevent complications and disability; For those who lose their labor force or are disabled, it is mainly to promote functional recovery and psychological rehabilitation, and provide family nursing guidance, so that patients can restore their living and working abilities as soon as possible, participate in social activities and prolong their lives.