Malignant tumors have become the leading cause of death for urban and rural residents in China, and their incidence and mortality rates are still on the rise. Since the causes of malignant tumors are still not well understood and there is a lack of effective treatment, tertiary prevention of tumors has become the key to reduce the incidence of cancer and control cancer. In fact, this is not a new understanding. As early as more than 2,000 years ago, the idea of tertiary prevention was embodied in the traditional Chinese medicine of treating the untreated diseases. As stated in the Nei Jing, “The sage does not treat the sick before they get sick, and does not treat the chaotic before they get chaotic. If the disease has become and then the medicine, chaos has become and then the cure, like thirst and wear well, bucket and cast cone, is not also late?” It vividly embodies the academic thought of “early prevention” and “first prevention” and emphasizes the preventive view of “prevention before it happens”. The idea of “treating the disease before it happens” is widely applied in nursing work, which can promote nursing work to better adapt to social development and ensure the implementation and implementation of the nursing work goal of “promoting health, preventing disease, restoring health and alleviating suffering”. Therefore, it is the task and responsibility of modern medicine to develop the concept of treating the untreated diseases and to combine the treatment of untreated diseases with modern medicine to actively improve the state of subhealth. At present, this idea has shown its importance not only in the prevention and treatment of chronic diseases such as hypertension and diabetes, but also in the field of tumor prevention and treatment. The spirit of treating the untreated disease, which encompasses the core ideas of primary prevention, secondary prevention and tertiary prevention nowadays, deserves full attention. Medicine is not only the science of disease, but also the science of health. The purpose of medicine is not only to cure the disease, but also to make people not to get sick. The primary prevention of tumor is etiological prevention, which is an important link of tumor occurrence. We should re-understand “prevention-oriented”, learn “prevention-oriented” and really achieve “prevention-oriented”. We should re-understand “prevention-oriented”, learn “prevention-oriented”, and really achieve “prevention-oriented”. In secondary school, we have learned the law of mutual change of quality in the development of things – when the quantity of things reaches a certain degree, there will be a qualitative change, and after the new quality is created, there will be a new quantitative change on the new basis, and the cycle will continue to develop. If this state is not corrected in time, it is very likely to cause psychosomatic diseases, including: psychological disorders, irritability, insomnia, digestive disorders, abdominal distension, panic, chest tightness, etc., and even the feeling of wanting to die, but there is no organic problem. People in a sub-healthy state are generally not life-threatening, but if they encounter a high level of stimulation, such as staying up late, losing temper and other stressful conditions, sudden death can easily occur, which is often referred to as “death by overwork”. Gao Wenhuan, Gao Xiumin, He Yong, Wang Junyao, etc. are related to “death from overwork”, examples abound. Some experts have analyzed that China is now becoming a country with a high incidence of “overwork death”. In addition to the complex social factors, more importantly, they do not know enough about health. This part of the population is in a state of subhealth, is the quantitative change in the process of disease. Sample survey shows that about 60% of our population is in a subhealthy state, and with the increase of life pressure, this proportion is increasing, so the current focus of preventive medicine is on the treatment of subhealthy state. It is predicted that the focus of medicine in the 21st century will be the research on the prevention and treatment of “subhealth”. In any disease, it is from unwell to sick, from unformed to formed. Therefore, doctors should not only be good at treating diseases, but also be good at knowing the future diseases. Zhang Zhongjing’s saying of “treating the disease before it occurs” is the pursuit of all good doctors’ state of mind and the highest requirement for a good doctor. The research results over the years show that the only way to reduce the incidence of tumor is to prevent the cause of the disease. Determining various risk factors affecting the occurrence of malignant tumors and finding susceptible people is the key to cancer prevention. For example, it has been clearly established that smoking is positively correlated with the occurrence of lung cancer, and quitting smoking can reduce the incidence of lung cancer, which has become a reality in the United States. Effective treatment for pre-cancerous lesions to prevent them from becoming cancerous is in line with the academic thought of “prevention of changes from both diseases” in Chinese medicine. For example, removing precancerous lesions by laser cautery and local excision can prevent the occurrence of cancer. As a doctor, we should make full use of our knowledge and take the initiative to eliminate as much as possible the factors that lead to the subhealthy state, such as correcting the bad habits, improving the diet and nutrition structure, enhancing physical fitness, etc., so that more people can establish a healthy lifestyle, enhance the awareness of self-care, and establish the concept of “treating the disease before it happens”, which will greatly reduce the incidence of cancer. The incidence of cancer will be reduced to a great extent. Secondary prevention of tumor is mainly about early diagnosis, early detection and early treatment. It requires extensive screening and screening of tumors, monitoring of high-risk groups of tumors, improvement of early diagnosis, early treatment of pre-cancerous patients, and reduction of adverse effects of radiotherapy and chemotherapy. In the treatment of the untreated disease, the ideas of “supporting the righteousness and cultivating the root”, “preventing the disease before it occurs” and “preventing the change of the disease before it occurs” fully reflect the secondary prevention of tumor. To carry out large-scale group screening in areas with high incidence of tumors and high-risk groups, early detection of patients and timely prevention and treatment are effective methods to prevent malignant tumors. Alpha-fetoprotein (AFP) is highly expressed in primary liver cancer and the compliance rate of the test results is also high, which can be used as one of the indications for early diagnosis of liver cancer. At present, cancer treatment is still inseparable from surgery, radiotherapy and chemotherapy, but the trauma of surgery and the toxic side effects of radiotherapy and chemotherapy often bring great pain to patients. In tumor treatment, traditional Chinese medicine such as “Fu Zheng Pei Ben” is often used in combination with surgery, radiotherapy and chemotherapy, which can significantly reduce the side effects of treatment, increase the patient’s resistance to disease, and prolong the patient’s survival or even cure. As for the side effects of radiotherapy and chemotherapy, we can “prevent the disease before it happens”, that is, we should take active measures before or after the occurrence of various side effects of radiotherapy and chemotherapy to reduce the chance of side effects, reduce the severity of various symptoms, and improve the patient’s quality of survival and tolerance to treatment. For example, the incidence of myelosuppression after high-intensity chemotherapy is extremely high, and timely application of cell growth factors can effectively reduce the severity and incidence of myelosuppression. “In particular, measures can be taken to reduce the incidence of late-onset radiotherapy side effects such as radiation encephalopathy and radiation pneumonia. For example, clinical treatment methods such as nourishing Yin, moistening dryness and invigorating blood are used to prevent and treat late onset radiotherapy side effects. As a doctor, we should also pay attention to psychological treatment, establish a good communication relationship with patients, and apply various psychological therapies such as guidance, encouragement, suggestion and transfer to build up patients’ confidence to overcome the disease, promote the healing of the body and stop the deterioration of the disease, which can often achieve twice the effect with half the effort, and also “treat the disease before it happens”. It is also called “treating the untreated disease”. The goal of tertiary prevention of tumor is to prevent the deterioration of the disease and prevent disability. Its task is to adopt multidisciplinary diagnosis (MDD) and treatment (MDT) to correctly select reasonable or even the best treatment plan in order to extinguish cancer as early as possible, try to restore function, promote recovery, prolong life, improve quality of life, and even reintegrate into society. The main methods include research and formulation of reasonable treatment plans; comprehensive rehabilitation and nursing guidance; strengthening functional and physical exercise; and reasonable living and diet arrangements. Through preventing and intercepting metastasis, patients can obtain comprehensive rehabilitation in the process of surviving with cancer, or through Chinese medicine to adjust the bias of yin and yang of human body to restore its relative balance and prevent tumor recurrence and metastasis to a certain extent, which not only makes the treatment mode change, but also questions the evaluation of traditional tumor curative effect. Especially the development of targeted drugs in recent years, it not only provides a new means for tumor treatment, but more importantly, it may change the criteria for judging the efficacy of traditional tumor treatment, combined with the understanding that malignant tumor is not just an individual disease, but a local manifestation of systemic lesions, which makes us realize that tumor treatment not only lies in “finding, destroying and eradicating”, but also in “finding, destroying and eradicating”. “In addition, we propose to treat malignant tumors as chronic diseases such as “diabetes” and “hypertension”, and by maximizing the body’s anti-cancer ability, we can improve the body’s immune system. We propose to treat malignant tumors as chronic diseases such as “diabetes” and “hypertension”, to maximize the anti-disease ability of the body, to reduce the disease load as much as possible, to control and reduce the harm of tumors to the body, and to maintain the good quality of life of patients in the long run, to “live peacefully” and “survive with tumors”. “Survival with tumor” also fully reflects the idea of treating the disease in the future in Chinese medicine. For example, if patients with mid- to late-stage cancer have their disease controlled through comprehensive treatment or simple Chinese medicine, there can be a group of cancer survivors. Although the masses in these patients are not completely eliminated, after long-term treatment with TCM, together with heart therapy, qigong, taijiquan, food therapy, medicinal food and other means of health rehabilitation, the patients can survive with cancer, or prolong their survival period, or improve their survival quality, which not only effectively prevents the metastasis of cancer, but also buys time for further eradication. In addition, on the premise of treating cancer with evidence, the application of food therapy and medicinal food, which are welcomed by patients, can support positive energy, stimulate stomach energy, promote appetite, enhance the immune function of the body and improve the general condition, which is also one of the important means of “treating the disease before it develops” and preventing metastasis. It has been proved that this kind of rehabilitation and prevention measures under the concept of “treating the disease before it happens” is much more effective in patients with advanced cancer than simply applying anti-cancer treatment. In conclusion, under the premise of how to reduce patients’ pain and cure diseases, the focus of medical research has gradually expanded from the “already sick” to the “not yet sick”, and most people are also aware of the impact of subhealth on their health. This is in line with the development of modern medicine. Tumor, as the number one cause of death of human life, has become the focus of attention. How to reasonably and effectively apply the theory of treating the untreated disease in TCM to the tertiary prevention of tumor is a serious requirement and test for our medical workers in oncology. The idea of treating the untreated disease in TCM is obviously ahead of its time and responsive, which fully reflects the preventive thought of TCM of preventing the disease before it happens and preventing the slightest bit. Inheriting the theoretical thought of treating the untreated disease in TCM is a sacred mission that can promote the development of modern medicine and generally improve the physical fitness of the social population. “It is not too late to mend the fold after sheep are lost.