Whether a lung nodule of 14mm is serious or not depends mainly on the cause of the lung nodule, and it is more serious if it is malignant. 1. Whether a pulmonary nodule is serious or not does not depend on the size of the nodule, but is closely related to the nature of the nodule. The main causes of lung nodules 14mm include benign lesions such as tuberculosis ball, lung misshapen tumor, bacterial lung abscess, and malignant lesions such as lung cancer. 2. In most cases, the prognosis of lung nodules caused by benign lesions is generally good after treatment, so the patient’s condition is generally not serious. However, lung nodules caused by malignant lesions are more serious and require prompt medical attention, surgical resection or radiotherapy or chemotherapy if necessary. If a 14mm lung nodule is found in the body through examination, further examination should be carried out to make a clear diagnosis, to clarify the nature of the lesion, and to find the primary disease and cooperate with the doctor for treatment.