wall cracks are typically superficial in nature as most of them are built of masonry blocks and plastered. it's the plastering that may be cracking due to weathering and exposure to extreme environment (ex: high temperature and high humidity). however, there will be cases that they also crack due to exssesive sagging of beams either that which it support or that on top of it and that is a case to worry.

if you can see your concrete flooring and beams having cracks, there you must worry more.