Although it cannot be said that tumors are caused by psychological and social stress, a lot of facts and animal experimental data prove that psychological factors have a close relationship with the occurrence of tumors. The United States once investigated the life history data of 250 cases of various cancer patients and found that 150 patients generally suffered from strong mental stimulation before the onset of cancer. The annual meeting of American medical psychology reported the personality characteristics of 120 cases of liver cancer patients, and the analysis confirmed that: introverted personality, bad psychology, social stimulation, long-term emotional depression and family disharmony are one of the main factors causing cancer. Mental and psychological factors induce tumor 1. Life events are the main stressors Life events are the main stressors in daily life, and they are also one of the main psychological factors that can easily lead to unhealthiness. Epidemiological studies show that chronic mental stress and high emotional stress caused by life events are related to the increased incidence of tumors. Clinical control shows that life events such as “family misfortunes”, “excessive work-study stress” and “incompatible interpersonal relationships” are important for cancer promotion in the history of cancer patients. Cancer etiology also shows that patients often experienced major life events within six months to eight years before the onset of cancer. The most pathogenic life event is the death of a first-degree relative, such as the death of a spouse, parent, or subsequent child. Widows have a high incidence of tumors. 2. Type C personality is prone to cancer Research in clinical psychology has found that there seems to be a relationship between personality traits and the occurrence of tumors. An American scholar divided 182 subjects into A, B and C categories according to their personality traits and observed them for 6 years to study the relationship between personality traits and disease rate. It was found that those with C personality traits (introverted personality, eccentric personality, superficially cautious, sometimes impulsive; although sentimental, but talented; sometimes demanding high goals, sometimes demanding very low) had higher prevalence and more tumor patients. Tumor patients are mostly silent and in a long-term lonely, contradictory, disappointing and depressing situation, especially manifested as anxiety and depression. Keeson pointed out: Lung cancer patients are mostly good at restraining emotions and less venting. Fox pointed out that denial, repression, despair, alienation, early loss of mother’s love, etc. measured by Minnesota Multiple Personality Inventory are related to the development of tumor. Research by Chinese scholars has proved that the following personality traits are prone to cancer: 1. sentimental and depressed 2. impatient and irritable with poor endurance 3. silent and indifferent to things 4. withdrawn and eccentric. Although personality traits are related to the occurrence of cancer, through personal cultural cultivation and efforts, having faith can implicitly influence and change the personality traits, thus reducing the occurrence of cancer. 3.Emotion may be the activator of tumor cells A lot of research shows that many tumor patients had a sudden major mental shock after long-term bad emotional stimulation before the disease. A psychological survey on malignant tumor patients found that people who restrain themselves, suppress anger, have insecurity and dissatisfaction are prone to malignant tumor. Therefore, scholars pointed out that “emotions may be the activator of tumor cells”. In the 2nd century A.D., the physicist Dong Lun found that women with happy moods were less likely to get cancer than women with depressed moods. In his well known monograph “Breast Cancer”, Nairn pointed out that emotional factors affect tumor growth. He cited the example of a patient who was stimulated by the death of her husband at the time of the onset of the disease. The tumor grew larger and larger thereafter, and the patient died soon after. In his classic work “Surgical Pathology”, Paget stated that biological depression plays an extremely important role in the development of cancer. He believed that deep depression, long unfulfilled wishes, and mental depression from disappointment are important complementary factors to other factors favoring tumor growth. Psychosocial factors can induce the occurrence and deterioration of tumor 1. dysfunction of nervous system Soviet scholars such as Bastersk found that animals with transplanted tumors have altered cortical activity and the frequency of impulses of affected nerves is reduced. 1982 federal German Homry pointed out when talking about the relationship between psychological factors and cancer that long-term mental tension and excessive life stress can make the brain electric field constantly short-circuit and occur wrong of the code, leading to cell mutation and causing cancer. Sten et al. found in guinea pig tests that disruption of the anterior hypothalamus can cause a decrease in antibody titers and inhibition and delay of allergic reactions. They suggested that alterations in the subcortical or hypothalamus could directly weaken the ability to fight cancer through immune response. 2. Endocrine dysfunction Many studies have proved that different types of stressful events can produce endocrine changes related to an individual’s ability to cope with stressful situations, and this endocrine response can change the immune ability of the body. Different hormone receptors (e.g. insulin, histamine and prostaglandin receptors) have been found to exist on lymphocyte membranes. Interactions between hormones and between hormones and receptors lead to reduced immune function and favor the growth of tumors. 3.Dysregulation of immune system supervision It is now believed that long-term mental and social factors causing stress and mind changes are one of the most important pathogenesis of tumor, and one aspect of pathogenesis is its causing immune dysfunction. Immune deregulation manifests abnormal differentiation and proliferation, which cannot be killed, destroyed and removed properly. The current understanding of immune mechanism has confirmed that strong emotional response can change the immune defense function of the body, and the suppression of immune defense function can contribute to the occurrence of tumor. Animal experimental fluid proves that: psychological tension can contribute to the development of tumor, for example, mice in a long-term stressful environment can increase corticosteroids, decrease T lymphocytes, degenerate thymus, and shrink lymphocytes involved in immunity.