Once a small nodule is found, a doctor should be asked to assess the probability of malignancy of the small nodule, taking into account the patient’s age, occupation, exposure history, smoking history, the imaging pattern and growth rate of the small nodule. In addition to this, if one of the following five conditions occurs, it should be taken seriously and it is recommended to go to an experienced professional doctor for diagnosis as soon as possible: 1) a halo around the moon; 2) nodules with horns and spines sticking out around them, like a hairy chestnut; 3) nodules with small translucent vacuoles; 4) nodules with blood vessels pulled in; 5) pleura with pulling.