Mild scarring is seen in the right lower zone of my lung, what does it mean? i don't even have history of tb. how do i get this?

Most likely: Past pneumonia or pleuritis. You should get tested for TB anyway and other infections, but at your age, cancer is not likely. Why did you get chest x-ray in the first place? If you are having symptoms, you should get to a doctor.

Information.: Scarring in the lung can occure for many reasons. Any type of occult infection can cause it. An asymptomatic blood clot can cause it. If it doen's cause a functional problem it may be you don't hae to worry about it. However, you should have periodic chest xrays to be sure it is stable and not progressive.