What are lung nodules and are they serious?

A pulmonary nodule refers to a round or oval lesion less than 3 centimeters in diameter found on chest CT imaging. These nodules typically appear as opaque areas within the lung. Pulmonary nodules can arise from various causes, including infections (such as pneumonia, tuberculosis), inflammatory diseases, benign tumors, or early-stage lung cancer. The presence of a single pulmonary nodule does not necessarily indicate a serious condition, especially if it is small and has well-defined edges, which makes it more likely to be benign. The severity depends on multiple factors, such as the size, shape, density, and number of nodules, the presence of calcification, and the patient's personal medical history (e.g., smoking history, family history of disease). Further evaluation may be warranted if the nodule is large, has an irregular shape or spiculated margins, or is accompanied by other symptoms such as hemoptysis or persistent cough.