The probability of lung cancer with shadows on CT lungs cannot be determined, and a variety of reasons can lead to shadows on the lungs. There are high density shadows and low density shadows when you have CT lungs with shadows. High density shadows are mostly seen in tumors, tuberculosis, inflammation, nodules, etc.; low density shadows are mostly seen in emphysema, alveoli, lung cavities, etc. Based on the CT shadow alone, the cause of the disease cannot be determined. In order to confirm the diagnosis of the disease, it is necessary to do further examination, including bronchoscopy, puncture biopsy examination and tumor marker examination. Lung cancer usually manifests as symptoms of cough, chest pain, blood in sputum, dyspnea, body lethargy, and fever, and it is suspected to have lung cancer if there are high density shadows on the lungs with symptoms of lung cancer when CT is done. People who have CT lungs with shadows need to consult the doctor in time, make diagnosis early, make individualized treatment plan under the guidance of physician, and don’t use medicine by themselves to avoid bad results.