Hi,
It may be due to broken rib or inflammation called as
costochondritis. You should perform an Xray to rule out
Rib Fracture. If there is no rib fracture than there is inflammation for which u should take antiinfammatory drugs such as
Brufen for 05 days.
I hope I am sucessful in solving your query If you have anything more to ask you can ask me
Regards,
Dr. Azhar Sattar