There are many reasons for the appearance of nodules in the lungs, including previous lung infections, previous history of tuberculosis, inhaled dust, pollution particles inside the air, and new growths inside the lungs. Whether it is a benign or malignant tumor, new growths are the reason for the appearance of nodules within the lungs. There are many reasons, such as environmental factors, diet, water, air, or living habits, including emotions, rest, sleep are related, this is not easy to say, it may be a multi-factorial situation. In addition to this, we should also pay attention to the situation of family genetic susceptibility factors, such as a family history of lung cancer, the emergence of lung nodules, it is more worthwhile to pay attention to whether it is because of genetic problems, such as gene mutation appeared in the new development of nodules in the lung. There is also in the process of checkups, CT follow-up can be seen in the production of new-onset nodules, these nodules sometimes it is difficult to say its etiology and the source of what exactly is the case, for example, there is no recent lung infection, there is no pneumonia, last year’s imaging was not nodules, and this year there is. In this case, the etiology is very difficult to tell, but when it is detected, it has to go into the process of further consultation and follow-up.