Medical research shows that psychosocial factors are important determinants of human health. Medical psychologists have pointed out that the prevalence of diseases in people with stable families, happy marriages, harmonious interpersonal relationships and trusted friends and relatives is significantly lower than that of people living alone or under heavy psychological pressure. About 50% of human diseases are related to lifestyle and behavior, and lifestyle and behavior are mostly related to psychological factors, and sometimes psychological factors even play a leading role. Now, cancer is still the leading cause of death among urban residents in China. Therefore, cancer prevention should also pay attention to psychological, behavioral, environmental, genetic and other factors. Mental trauma is closely related to cancer A scholar has conducted a retrospective survey on the causes of uterine cancer in 250 women. In 1977, German doctor Gromer investigated a large number of cancer patients and found that all of them had experienced long-term inner depression in the past. 1980, relevant experts made a retrospective investigation on 50 patients hospitalized in the oncology department of Baiqiu’en Medical University and 50 patients living in the internal medicine department at the same time, and counted whether they had experienced major mental traumas since they were 8 years old. The results showed that 37 (74%) of the oncology group had suffered major trauma, while only 15 (30%) of the internal medicine group had. These studies have shown that mental trauma is closely related to the development of malignant tumors. Character affects immune function Human character has plasticity, and its formation is related to each person’s living environment, cultural literacy, social status, as well as the influence of family, school education and social practice, so the cultivation of a good character should start from childhood. People with optimism, cheerfulness, integrity character, often show enthusiasm, frankness and helpfulness, easy to get the help and understanding of others, good interpersonal relations and fewer conflicts, when encountered in psychological stress, can also show a strong tolerance, thus protecting their own immune function. People with good character often have scientific worldview, correct outlook on life and dialectical thinking method, can better adapt to work, life and social environment, less worries and troubles, even if the bad emotions, but also can be quickly resolved by the self, and therefore has a more sound immunity. 1984, someone did Eysenck questionnaire test on 100 cancer patients and 100 healthy people, the results In 1984, 100 cancer patients and 100 healthy people did the Eysenck Adult Questionnaire Test, the results found that most cancer patients have nervousness, depression, anxiety, irritability, suspicion and emotional instability and other personality traits. Good mood helps to prevent disease Good mood comes from the understanding of objective things, good emotional state can make the brain and hypothalamus and other nervous system through hormones, neuropeptides, neurotransmitters and other information molecules, the role of the immune cells, so as to enhance their immune function, which is very beneficial to the prevention of disease and cancer. Among them, α-interferon can inhibit the occurrence of hemangioma and leukemia in children; tumor suppressor M can inhibit the occurrence of melanoma, lung cancer, bladder cancer, breast cancer, prostate cancer; leukemia inhibitory factor can inhibit the occurrence of leukemia; hepatocellular regulating factor can inhibit the generation of hepatocellular carcinoma cells, melanoma cells, and squamous carcinoma cells and so on. Some human cancers are caused by genetic inheritance, but there are structural genes and regulatory genes, and the latter can be expressed in a good direction due to people’s good diet, environment and psychological state, thus avoiding the occurrence of cancer. In the clinic, we often see that the same people with lung cancer, the same stage, the same cell type, the shorter ones die in less than a month, and the longer ones can live up to 7 or 8 years. Why? There is a saying in our clinic that one-third of cancer patients are scared to death, in fact, it is the poor psychological quality of these patients, they are scared by cancer, they give up, and their muscles can’t rise up to fight with cancer, just like fighting a war, when the general escapes, he will inevitably be defeated, and the cancer cells invade the vital organs, which will lead to death in a short period of time. Therefore, to treat cancer, the main thing is scientific treatment and positive and optimistic mindset.