Nodules in the lungs smaller than 5 mm usually do not cause clinical symptoms and are mostly found during physical examinations.
Common causes of pulmonary nodules include inflammatory pseudotumors of the lung, chronic pneumonia, granulomatous tissue growth, lung cancer, tuberculosis, and pulmonary malignancies. Most small nodules in the lungs smaller than 5 mm are considered benign nodules and are common in people who smoke, with a very small probability of being malignant.
If a lung nodule is found on physical examination, further CT or enhanced CT of the lung may be considered to clarify the general condition of the nodule, and if the nodule is considered benign, it should be reviewed 3 months after the examination; if the nodule does not change much, it should be reviewed in 6 months; if the nodule does not change much on each review, it should be reviewed once a year.
If the lung nodule is significantly larger or has a tendency to become malignant, a puncture biopsy of the nodule is needed; if it is found to be lung cancer, surgery is needed.
Lung nodules are closely related to factors such as smoking and air pollution, especially smoking, so avoid smoking or secondhand smoke as much as possible.