What are tell tell signs of lung cancer? I have coughed up blood, I have been having upper/middle back pain, and when I went to the doctor they said I had low vitamin d I just wanted a second opinion on what these symptoms might be.

Weight. Weight loss, spitting up blood, lack of appetite and energy along with abnormal cxr or ct chest (spot of chesr x ray or ct chest) are all suggestive of cancer. Sometimes coughing too hard/bronchitis can lead to blood in sputum as well besides lung cancer.
The. The ways to identify someone with lung cancer are dependent as to whether they are found by screening or symptoms. The major symptoms associated with lung cancer are cough, with or without blood (hemoptysis), chest pain, shortness of breath, and weight loss.