Hello Welcome to HCM It is very difficult to understand your case. You have not mentioned site of pain? Right sided pain or left sided pain or central pain? since how many days or hours or minutes your suffering from these symptoms? is there any association with breathlessness, fever, cough? Is there any history of trauma ? Sorry to say but you haven t given proper history. But at the age 13 it is rare possibility of heart related pain. Most common cause of chest pain in pediatric age group is costochondritis ( Inflammation of junction between rib cage and sternum or breastbone) which can be treated with simple anti inflammatory medications. Please take an appointment with your pediatrician or physician for detailed examination with history. Regards