Chronic chest pain, usually a throbbing pressure but sometimes a sharp, stabbing pain that lasts about 10-30s. affects both sides of chest. what is it?

Need more info: Not enough information give, so differential is very wide. Could be related to esophagus or stomach if happens after meals; both sides of the chest - unlikely to be cardiac, unless it occurs with exertion; how long does it last? Is it radiating? Is it related to taking deep breath? My advise is to see a doctor since you may need physical exam and ECG in addition to more history.

Highly Likely Benign: Assuming no previous pediatric heart or lung diseases (or undetected), you most likely are having musculoskeletal pain (do need to rule out a common cardiac disorder called 'Barlows'/'floppy mitral valve' which is BENIGN but could cause this-easy to diagnose w/ a stethoscope. What causes the pain- movement (musculoskeletal), exertion (cardiac), eating (GI/stomach0. Also common- ANXIETY and stress!