A small amount of pleural effusion is found in the left side of the chest through CT chest scanning, the specific treatment plan needs to be judged in conjunction with the cause of the disease, common causes include inflammation, tuberculosis, tumors and so on, and the specific treatment plan includes anti-infective treatment, anti-tuberculosis treatment and surgical treatment. 1. Inflammation: pleural effusion caused by pneumonia can be controlled by anti-infective drugs, commonly used drugs include moxifloxacin. 2. Tuberculosis: Intrapulmonary tuberculosis or tuberculous pleurisy can also produce pleural effusion, which needs regular treatment with anti-tuberculosis drugs, commonly used drugs include isoniazid. 3. Tumor: malignant tumors in the lungs can also cause pleural effusion, and the tumor can be radically resected through surgery, and the pleural effusion will gradually recover after the lesion is removed. If there is a small amount of pleural effusion, which does not improve and is accompanied by the symptom of breath-holding, it is necessary to consult a doctor in time for observation, and carry out standardized treatment under the guidance of a clinician after diagnosing the condition to avoid delay.