In ancient times, medical doctors in China have already noticed the role of mental factors in the occurrence and development of tumors and other diseases. Too much or too little of the seven emotions (happiness, anger, sadness, thought, grief, fear and fright) can lead to disturbance of the flow of qi and blood in the body, such as anger leads to upward qi, thought leads to qi knots, and fear leads to downward qi. Ancient medical practitioners have also pointed out that the development of breast cancer is related to women’s prolonged emotional disorders and depression. When a patient is diagnosed with cancer, fear, thought, anger, sadness, loss of confidence and worries all day long, if these are not corrected in time, the treatment effect will be seriously affected. In our clinical work, we have seen that under the same medical condition, some patients who are “open-minded” and have a strong will to fight against the disease often have a much better outcome than those who are scared and overwhelmed by cancer. Even the best treatment will be in vain if the patient is mentally destroyed. Of course, correct and timely diagnosis and treatment will, in turn, give patients confidence in recovery and strengthen their morale if they achieve better results. Emotion can both “cause cancer” and “cure cancer”. The most important thing for cancer patients is to avoid phobias. Psychologically, due to ignorance of cancer, cancer is often regarded as “incurable disease”, “terminal disease”, “death sentence”, etc., thus creating a psychological fear. As soon as they hear that they have cancer, they think “everything is finished” and wait for death, so they are negative and pessimistic. Such patients often do not seek medical treatment seriously and do not want to cooperate with the treatment, so they often do not get good results. The reason for their fear is that they have heard a lot about “cancer is incurable” but know very little about the cured cases, and they do not know much about the progress and development of medical treatment for cancer. In addition, they are afraid of the damage and pain that may be caused by the treatment methods, such as fear of aesthetic effects after mastectomy, fear of hair loss after chemotherapy, fear of toxic side effects of radiotherapy, etc. If one can pull oneself together, face the reality, believe in science, and be strong enough to meet various challenges, the fear will be greatly reduced and one will adopt a more positive attitude to accept the various reactions brought about by the disease and treatment.