Possible causes of fever for ten days after surgery include postoperative wound infection, postoperative pneumonia, cold or use of certain medications after surgery, etc. The cause of the disease needs to be found and treated in time. 1. Post-operative wound infection: if you still have fever ten days after surgery, you may have post-operative infection, and you need to go to the hospital for examination and treatment in time. 2. Post-operative pneumonia: some people have long bed rest after surgery, which can lead to post-operative pneumonia and fever can appear. It is necessary to seek medical treatment in time and do lung CT for identification if necessary. 3. Colds: Fever, nasal congestion, runny nose and other symptoms without other discomforts can occur after a cold. 4. Certain medications: Some people use certain medications and are allergic to them, which can also cause fever. There are more reasons why you keep having fever for ten days after surgery, so you should consult your doctor in time to clarify the cause of the disease and treat it in time.