Whether a 2-centimeter benign pulmonary nodule is serious depends on the cause of the disease. Benign lung nodules can be caused by granulomatous lesions, fungal infections of the lungs, and tuberculosis. With aggressive treatment, the prognosis is usually good. 1. Pulmonary sarcoidosis: progresses more slowly. It may be related to lung infections, immunologic factors, environmental factors, smoking, etc. It usually resolves on its own. If the granuloma is large, it can be removed surgically. 2. Lung fungal infections: a variety of fungi can cause fungal infections in the lungs, causing 2-centimeter benign pulmonary nodules, also a kind of lung inflammation, usually needing antifungal treatment, after which it can gradually improve. Fungal infections caused by sensitive bacteria are usually not serious. 3. Tuberculosis: It can be accompanied by cough, sputum, low fever in the afternoon and weight loss. The prognosis for tuberculosis treated with standardized treatment is generally good if it is a non-drug-resistant strain. However, tuberculosis caused by drug-resistant strains is more difficult to treat, with severe systemic symptoms and a long course of treatment, which is more serious. There are other causes of 2-centimeter benign pulmonary nodules. It is recommended to consult a doctor in time to identify the cause and take scientific and effective treatment measures according to the cause of the disease.