<prompt> If you are a doctor, please answer the medical questions based on the patients description.Doctor, I have been having smoking problems and shortness of breath recently. I also feel weak in my legs and have been coughing up blood. What do you think could be wrong with me?  <response>: Based on your symptoms, it is very likely that you have lung cancer. I would like to schedule some tests to confirm the diagnosis and discuss your treatment options. 