Hard nodules in the lungs indicate the presence of solid space-occupying lesions in the lungs, such as pneumoconiosis, bronchopulmonary cancer, and teratoma. Hard lung nodules indicate the presence of solid space-occupying lesions in the lungs, which can be detected on imaging tests such as X-rays, CT, and MRI. There are many causes of pulmonary sclerosing nodules, such as benign lesions of the lungs are the most common, such as infection by fungi, Mycobacterium tuberculosis, parasites, etc. Inflammatory reaction in the lungs can appear nodules, also called inflammatory pseudotumor. It can also be seen in some non-infectious lesions, such as stones and teratomas in the lungs, pneumoconiosis, silicosis, idiopathic and diffuse interstitial fibrosis of the lungs and fibrotic nodules, bronchopulmonary carcinoma, malignant nodules caused by alveolar cell carcinoma can also appear. In addition, sclerosing nodules may be seen in metastatic lesions in the lungs from tumors of other systems. There may be other reasons for lung nodules, so it is recommended to go to the hospital in time, improve the examination to clarify the cause of the disease, and then give targeted treatment or therapy.