A 70-year-old man with a 2.6-cm nodule under the chest wall of the posterior segment of the right upper lung does not need surgery for a benign nodule, but surgery should be considered for a malignant nodule. If the nodule under the chest wall of the posterior segment of the right upper lung of a 70-year-old man is 2.6 centimeters, it may be caused by lung inflammation or viral infection, etc., and a CT examination of the chest can be done to clarify the nature of the nodule. If the nodule is benign, it can be treated conservatively, such as lifestyle intervention, medication, etc., and anti-inflammatory and anti-viral drugs, such as norfloxacin and acyclovir, etc., can be taken according to the doctor’s instructions, and surgery is not needed. If the nodule is malignant, but also with a professional doctor for PET-CT, puncture biopsy, after the doctor diagnosis to clarify the type of nodule, can be combined with the actual physical condition of the elderly, to consider whether to choose surgical treatment. If the physical condition of the 70-year-old man is not suitable for surgery, he should actively cooperate with the doctor to formulate a reasonable treatment plan. During the treatment period, once the old man has any abnormality, it is recommended to go to the hospital as soon as possible for consultation and treatment.