When a nodule in the lung reaches a diameter of 1 cm, it is more likely to be considered a malignant tumor, and the need for surgery should be decided by a clinician after a comprehensive assessment of the nodule’s character and evolution. Mixed ground glass nodules 1 cm may be due to malignant tumors or lung infections. 1. Malignant tumor: Lung cancer is a malignant tumor originating from the bronchial mucosal epithelium or alveolar epithelium of the lungs. The diagnosis can usually be clarified after lung imaging, review of the nodule assessment, and then sputum examination for cancer cells, bronchoscopy, or puncture biopsy of the nodule. Surgical treatment, i.e. surgical resection, is the first choice and the most important treatment for lung cancer. 2. Lung infection: if the nodules are caused by various infections, drug treatment is often the first choice. For bacterial infection, commonly used antibiotics include cefixime, amoxicillin, azithromycin and so on. For tuberculous infections, anti-tuberculosis drugs such as isoniazid and rifampicin are required for treatment. If a 1-centimeter mixed ground-glass nodule is detected in the lungs, you need to seek medical attention as soon as possible to avoid delays.