Lung nodules — or pulmonary nodules — are small growths that can develop in the lungs. By definition, they are no larger than 3 cm, or about 1.25” across. Anything bigger than that is considered a mass.  

Lung nodules are very common. But most lung nodules are not due to cancer.  

So, why do lung nodules even form? Do they ever cause any symptoms? And, what should you do if you find out you have one?&...