Chest x ray shows subtle scarring in left lung base after pnemounia and pleurisy. is this bad and can it become a problem?

Mgt: A virtual consult can be booked online, so that the imaging may be viewed. From your description, this type of residual scarring should not result in a decrease in lung function.

That is: not an unexpected finding following pneumonia, and probably not clinically significant assuming your symptoms have resolved. Talk to your doc about the results.