The severity of the right upper lung nodular shadow is determined by a combination of the size and nature of the nodule. Generally nodules are classified into three cases: ground glass nodules, partially solid nodules and solid nodules. If the nodule is less than 5mm, it is mostly a chronic inflammatory change, no specific clinical symptoms do not need to give treatment, generally dynamic follow-up 1 year high resolution CT once can be. If the nodule is between 6-8mm or even larger than 8mm, accompanied by lobar, short burr, pleural pulling sign, pleural depression sign, etc., it indicates that it is very likely to have developed into early-stage lung cancer, and enhanced CT examination of the chest and percutaneous lung aspiration cell histological biopsy are needed to further understand whether it has developed into early-stage lung cancer if necessary. If the nodule has developed into early lung cancer, early intervention by a thoracic surgeon is needed to avoid delay in treatment. Therefore, whether a right upper lung nodule is serious or not depends mainly on the nature of the nodule to decide.