A cavity in the lung is not necessarily lung cancer. CT examinations are needed to diagnose lung cancer, and pathology is needed for the final diagnosis. When a CT examination of the lungs is performed, sometimes cavity-like changes in the lungs are found, which in most cases are a reaction to tuberculosis or other inflammatory conditions in the lungs. In order to determine whether it is lung cancer, sometimes it is necessary to perform a puncture under the guidance of CT to take the pathological tissue of the cavity suspected of lung cancer and observe it under the microscope, and the final result needs to be observed under the microscope to be confirmed. When a cavity is found in the lung, it is important to go to the hospital for professional diagnosis and treatment as soon as possible, and if necessary, pathological examination should be performed to determine whether it is lung cancer.