Hi, Thank you for providing the brief history of you. A thorough clinical assessment is advised. As you were running and jumping with all of a sudden there was some swelling and pain in the shin, it could be muscular, as the leg area has very thinner muscles and sudden symptoms occurring are common. On a safer safer side, getting a vascular scanning can be performed, post which is any abnormality is there in the vascular system can be treated accordingly. If its just a pain and swelling, then undergoing physical therapy like - therapeutic ultrasound therapy and TENS therapy will be good to reduce pain and inflammation. In my clinical practice such symptoms are common and nothing much to worry. Regards Jay Indravadan Patel