All kinds of human psychological phenomena are the reaction of objective things in the brain. The brain is the higher center of the human body, which plays a dominant or mediating role in all functions and activities of the body. Modern medical research proves that violent mood swings can disrupt the normal functioning of the brain, making the internal functions of the body dysfunctional and causing many diseases. Pavlov pointed out that “all stubborn, heavy anxiety and anxiety, will certainly open the door to a variety of diseases.” It was found that of the 170 cases of death within a short period of time after a strong stimulus and a sharp fluctuation in feelings, 59% died after news of personal misfortune and great loss; 34% died in situations of danger or threat; 7% died in ecstasy. The Soviet scientist Pirogov observed that the wounds of the victors heal faster and better than the wounds of the losers. The mental state of people in daily life has a significant impact on cardiovascular function. For example, it is common to see a rapid heartbeat when emotionally excited, and facial blood vessels dilate when shy. Clinical observation, angina often occurs when emotional excitement, this is due to the nervous system in a highly excited state during emotional or stressful brain work, the content of theophyllamine in the blood increases, causing vasoconstriction, blood pressure increases, increasing the oxygen consumption of the myocardium, thus sudden onset of angina, serious cases can even induce acute myocardial infarction. People generally have a better appetite when they are happy, and a reduced appetite when they are sad. Studies have shown that when emotions change, the vagus nerve is excited and for function is affected. In addition, emotional changes in intestinal function is also very obvious, such as anger, anxiety is the colon hyperfunction, resulting in continuous contraction of the colon, narrowing of the colon, increased secretion of lysozyme, intestinal conjunctiva becomes brittle, and spot bleeding, and even erosion, ulcers. A psychologist did an experiment in which two sheep were put in two cages and given the same survival conditions, but the only difference was that one of the cages was near the wolf’s den. The experiment showed that under the same survival conditions, the sheep that leaned into the wolf’s den eventually developed ulcer disease due to fear and anxiety. Afterwards, the diseased sheep was moved far away to an environment without wolves and given appropriate treatment, and the ulcer and gradually healed. If this sheep was placed next to the wolf’s den again, the ulcer disease would recur again. The above experiment shows that the stimulation of mental factors plays an important role in the formation of ulcers. Experts have found that when a person is stimulated by strong and persistent tension, a series of emotional changes, such as anger, fear and anxiety, will occur. These emotional changes can directly affect the control of the cerebral cortex center on the subcortical heat stroke, and through changes in the neuromodulation mechanism to disrupt the physiological function of the stomach, is the gastric mucosa congestion edema, gastric peristalsis enhanced, gastric acid secretion increased significantly, and even erode the gastric mucosa. Too much psychological tension can lead to serious disorders of the nervous system, causing a variety of neuroses, including neurasthenia, hysteria and obsessive-compulsive disorder, and in serious cases can also cause insanity and behavior disorders. Most of the so-called reactive psychoses are caused in this way, and it is a mental disorder caused by strong, sudden or persistent mental factors. Endocrinologists tell people that excessive stress, long-term anxiety and other mental burdens are important factors triggering hyperthyroidism. From the complaints of “hyperthyroidism” patients, it can be seen that the mood fluctuation can be caused by promotion, going abroad, promotion and promotion, etc., while the continuous mental tension caused by overwork and study is closely related to the onset of the disease. Although there are many causes of cancer, a lot of scientific experiments in recent years have confirmed that adverse psycho-social stimuli are a strong cancer-promoting agent, and this has been confirmed by animal experiments. If dogs were divided into two groups, one group was in a state of prolonged panic and the other group was living in a quiet environment. As a result, three of the six dogs in the first group died of cancer, and four dogs in the second group were safe and sound. Modern physical and mental medicine experiments have confirmed that adverse psychological factors, excessive tension and stimulation, depression and sadness can degenerate the thymus gland through cholesterol-like effects, cause immune lymphocyte maturation disorders, inhibit immune function and induce cancer. All of the above shows that psychological factors play an important role in the occurrence, development and prevention of diseases. To prevent the occurrence of diseases, we must pay attention to mental health.