A thread on the side of the incision after lung nodule surgery is usually related to the wound not healing, rejection reaction, wound infection and other factors. 1. The wound has not healed: a thread on the side of the incision after lung nodule surgery may be caused by the wound not healing, and it takes some time to recover from the reaction of the thread after lung nodule surgery. 2. Rejection reaction: if the incision is infected after pulmonary nodule surgery, the thread will become a foreign body and be discharged on the side of the incision. 3. Wound infection: there is a thread on the side of the incision after lung nodule surgery may be the local location of the wound infection, which leads to poor absorption of the thread by the tissue cells, causing the patient to have a thread on the side of the wound. It is recommended that patients should go to the hospital in time for examination and symptomatic treatment under the guidance of the doctor.