Chronic obstructive pulmonary disease, also known as chronic obstructive pulmonary disease, is a manifestation of chronic bronchitis with recurrent attacks leading to lung dysfunction, mainly manifesting as dyspnea, cough, emphysema, etc. The main purpose of lung CT is to detect increased lung translucency, while lung cancer is a malignant tumor of the lung. Therefore, further examination of the occupying lung lesions, such as puncture or fiberoptic bronchoscopy, can find cancer cells in the pathological tissue to confirm the diagnosis of lung cancer. It is a malignant tumor that is fundamentally different from the benign disease of slow lung obstruction, so slow lung obstruction is not lung cancer, and slow lung obstruction does not lead to lung cancer.