A lung nodule of 9mm is considered more serious. Nodules larger than 8mm in diameter are generally more serious and have a malignant tendency, requiring further examination of thin-layer enhanced CT or percutaneous lung aspiration biopsy to clarify their nature. If the examination does not have malignant tendency, it is necessary to carry out regular follow-up in three months to six months after the examination, if the nodule does not shrink in the follow-up process, on the contrary, it is considered that the malignant situation is larger, and it is necessary to carry out surgical resection, if the nodule shrinks in the follow-up process, it can be changed to half a year to review, and the follow-up time is not less than three years. Lung nodule 9mm need to consult the doctor in time, under the guidance of the physician to clarify the nature of the nodule, the next step in the diagnosis and treatment.