A shadow in the lungs and a heavy cough can be seen in pneumonia, tuberculosis and lung cancer. 1. Pneumonia: Pneumonia can be categorized into bacterial pneumonia, viral pneumonia, fungal pneumonia, mycoplasma pneumonia and chlamydia pneumonia. Pneumonia can be seen in the shadow of lungs on imaging, and the specific imaging features of different types of pneumonia are different. Clinical manifestations are cough, sputum and fever. If you have pneumonia, you should actively cooperate with the doctor to carry out anti-infection treatment, light diet, supplemental nutrition, regular work and rest to promote recovery. 2. Tuberculosis: Tuberculosis is a respiratory infectious disease caused by infection with Mycobacterium tuberculosis. The imaging of tuberculosis shows polymorphic shadows, i.e., infiltrating shadows, nodular shadows, and fibrocalcified shadows can exist at the same time, with non-uniform density, which mostly occurs in the apical posterior segment of the upper lobe, the dorsal segment of the lower lobe, and the posterior basal segment. Clinical manifestations also have the symptom of cough, and may be accompanied by emaciation, chest pain, hemoptysis and so on. Tuberculosis should be promptly treated with standardized anti-tuberculosis treatment in hospitals or disease control. 3. Lung cancer: Lung cancer can be seen as shadow on imaging, with symptoms of cough, mostly dry cough, accompanied by hemoptysis, low fever, hoarseness, emaciation and other symptoms. If there is a shadow in the lung with heavy cough, it can also be seen in heart failure and other diseases, which should be immediately perfected in the local hospital for examination and further treatment after clear diagnosis.