Most cases of subpleural nodules are not serious, while a few cases may be metastatic malignant tumors, which are more serious. The presence of a nodule under the pleura needs to be evaluated on the basis of the medical history as well as the nature, size, and morphology of the nodule, and cannot be generalized. Most people find small subpleural nodules on physical examination. These nodules are generally benign and are often calcified foci of inflammation or tuberculosis left behind by healing, so these cases are not dangerous. A few people may have a history of malignant tumors, such as breast cancer, colon cancer, etc. If multiple subpleural nodules appear after surgical treatment, they may be metastatic cancer foci, which is a more serious situation. If subpleural nodules are found, it is recommended to seek medical treatment in time to clarify the nature of the nodules and treat them accordingly to avoid aggravation of the condition.