1 day history of pain may be associated with strain or trauma. If she has been working out, bench press workout tends to cause similar pain which lasts for just a few days. Examination is required to get a better idea. There's another condition called Costochondritis which is the inflammation of the joint between the Sternum and the ribs.

Reasons can be many Take pantop 40 empty stomach Consult if sever pain Take paracetamol for pain

Viral or just strain. Need to consult for proper assessment and guidance.