Sub-health has a history of more than 10 years in foreign countries, but in China it was proposed only in May 1996, and a number of domestic conferences have been held. According to relevant statistics, about 15% of the people in our country are healthy, 15% are unhealthy, and 70% are in a state of subhealth. Sub-healthy state refers to the human organism, although there is no obvious disease, but showing one more and three less performance, that is, more fatigue, reduced vitality, reduced responsiveness, reduced adaptability of a physiological state, although there is no disease, but the self-perception of all kinds of uncomfortable symptoms, is between health and disease of a physiological function of a state of low, also known as the ” organism third state It is also known as “the third state of the organism” or “gray state”. “Sub-healthy state” is a dynamic state of change, may develop into the second state, i.e. disease, can also be restored to the first state through treatment, i.e. health. Medical experts believe that sub-healthy state can easily lead to tumors, cardiovascular diseases, diseases of the whoosh and digestive system and metabolic diseases, which all have a slow development process, beginning with the manifestation of sub-healthy state, when not paying attention to it can easily be developed into a real disease. Among them, the sub-healthy state of the whoosh system is a cause for concern. Due to colds, coughs, chest tightness, shortness of breath and other symptoms are commonplace, and do not cause people to pay attention, so when people can not stand, are generally in a state of disease. When the human body is in a “sub-healthy state”, the respiratory system often shows the following symptoms: cough, sputum, shortness of breath, fever are common symptoms of the respiratory system. Sometimes these symptoms reflect the early manifestation of the disease, and after active treatment, can be quickly improved. Normal adults whistle 16 to 20 times per minute, the ratio of the number of times they whistle to their heartbeat is 1:4, and it is not normal to whistle less than 10 times per minute or more than 24 times per minute. The increase or slowing down of the number of whistles and the change in the rhythm of whistling are not only pathologies of the respiratory system itself, but also reflect systemic diseases. If the number of whistles per minute is more than 30, there may be high fever, central system pathology, endocrine system pathology, airway obstruction or lung inflammation, pulmonary fibrosis. If whistling is fast or slow, it may be a central nervous system disease, such as cerebral hemorrhage, increased intracranial pressure, etc., i.e., tidal whistling (a type of whistling in which the shallow slow whistling becomes deep fast whistling and then gradually turns into shallow slow whistling, followed by a pause in the whistling). However, tidal whistling can also occur in the elderly during deep sleep and should be recognized as such. There are also some patients with hyperventilation syndrome, i.e., continuous deep whistling, then deep inhalation, sighing before feeling comfortable, this kind of people have no organic lesions, check chest radiographs, lung function, blood tests, etc. are not abnormal, after whistling training can be restored to normal, but many people are therefore in a state of misery, and always think that they have an incurable disease. Cough is a kind of protective reflex action of the airways, mostly from the mucous membranes of the airways, and partly from the organs and tissues outside the airways. Inflammation of the airways, secretions or foreign body stimulation, pressure or pulling of the airways, pleura, other internal organs such as heart, esophagus, stomach and other stimuli can reflexively cause coughing. Early manifestations of colds and bronchial asthma are cough, especially chronic cough after colds, may be insidious asthma, such as early treatment according to asthma, may be cured, otherwise, it may become typical asthma. Acute bronchitis is also manifested as cough, such as active treatment, can be quickly improved, otherwise, it will be transformed into chronic bronchitis. Cough should pay special attention to the accompanying symptoms. If irritating cough is accompanied by hemoptysis, one should be highly alert to lung cancer. According to relevant experts, the incidence of lung cancer in China is currently growing 26.9% per year, and if control measures are not taken in time, by 2025, China’s lung cancer patients will reach 1 million, becoming the world’s first big country with lung cancer. “The mortality rate of lung cancer in China was 7/100,000 in the early 1970s and 17.5/100,000 in the early 1990s, while the figure is 40/100,000 now. Compared with 30 years ago, the lung cancer mortality rate has increased fivefold.” Why the incidence and mortality rates of lung cancer have increased so rapidly is related to the increase in lung cancer predisposing factors on the one hand, and atypical early symptoms of lung cancer on the other. It is clinically found that 80% of lung cancer patients are already in advanced stage when they are found, losing the time for surgical treatment. Therefore, for the high-risk groups of lung cancer, such as male smokers over 40 years old, who have irritating cough, hemoptysis and chest pain, they should actively find out the causes and strive for early diagnosis and treatment. There are also 1/3 of lung cancer patients who are asymptomatic in early stage, so it is very important to have regular medical checkup every year. For the elderly with unexplained emaciation, fatigue and weakness, or change in the nature of the original cough, chest X-ray should be examined, and chest CT and PET-CT should be done if necessary to exclude lung cancer. There may be a small amount of sticky white sputum in bronchitis. If there is more sputum and yellow sputum, we should find out whether there is pneumonia, lung abscess or bronchiectasis, etc. If the cough is accompanied by fever, we should check the chest radiograph. If cough is accompanied by fever, it is usually a manifestation of lung inflammation. If there is low fever in the afternoon, night sweating, emaciation, etc., it is mostly tuberculosis, and chest X-ray and sputum should be taken to look for tuberculosis bacteria, and experimental treatment is feasible if necessary. Chest pain is also a common symptom of the respiratory system, local hypoxia, inflammation, tumor infiltration, tissue necrosis, as well as physical and chemical factors such as stimulation of the sensory nerves in the chest can cause pain. Such as pleurisy, chest wall soft tissue injury, intercostal neuritis, chest wall tumors. Early herpes zoster without skin lesions mainly manifested as chest pain, myocardial infarction, cholecystitis, esophagitis, etc., can be manifested as chest pain, but the location of the pain, the nature of the pain are different, as long as vigilance, comprehensive examination, generally will not be misdiagnosed. Chest tightness and shortness of breath are also common symptoms of the respiratory system, but these symptoms are not only caused by diseases of the respiratory system, but also by other diseases such as brain lesions, cardiovascular system lesions, neurological system lesions, endocrine system lesions and so on, so-called “one disease, many symptoms, one disease, many diseases”. Therefore, clinically, we should strictly distinguish the lesions caused by different systems and the presence or absence of organic lesions. As we can see from the above, the subhealthy performance of the respiratory system may be the early manifestation of the disease, and it is difficult to distinguish it from the disease itself. Cold is a common clinical disease, generally believed to be caused by viruses, but in essence, it often occurs on the basis of the patient’s fatigue, decreased resistance, and so on, and it is an important manifestation of the state of sub-health. If a cold occurs repeatedly, or a cold does not heal for a long time, it often suggests a state of illness. Therefore, the symptoms of the respiratory system must not be trivialized or ignored, it is the barometer of the state of sub-health, but also the typical characteristics of the disease state, its disappearance or persistence, markers of the body in what kind of functional state, should cause the doctor and the patient a high degree of vigilance.