This is a hard question to answer with out having quite a few more details about what type of lung surgery you would be undergoing and what your underlying medical condition is. Typically, lung surgery might be performed in the setting of emphysema (to improve lung function) or lung cancer (to remove the affected portion of the lung. Lung transplant surgery is also used in patients with emphysema, cystic fibrosis, and other chronic conditions that affect the lungs. Finally, various biopsy
procedures of the lungs are used to diagnose underlying conditions.
These procedures range in complexity from minor (biopsy) to major (lung transplant) and obviously their complications and risks vary in the same way. Nevertheless, some basic risks of any type of surgery on the lung (or elsewhere) would include infection, bleeding, collapsing of the lung, or trouble from the anesthesia medications.
You will need to talk to your lung doctor
in order to get a better sense of what other complications or risks might be associated with the particular type of surgery that they are proposing for your case. I am certain that they will be happy to discuss your concerns and answer all of your questions at any time.