3 month repeat ct scan recommended due to "a few non-specific lymph nodes in the sub-plueral area in chest" is this serious? what could it mean?

CT scan is a good test to evaluate any suspicious nodule in the lung. It will show any such a lesion in a much better detail as compared to a Chest X-ray. Most such nodules are scar tissue left behind from past lung infection. Therefore they tend to be benign. There is a remote chance that a nodule turns out to be due to early tumor in the lung. So it is important to stay on top of this situation

If you have a smoking history, family history of lung cancer, the risk is higher. Other causes include ling infections. A virtual consult with HTMG is available.