Shin splints cause pain in the shin, the front part of the lower leg. They can also cause swelling. The pain is most likely from repeated stress on the shinbone (tibia) and the tissue that connects the muscle to the tibia.
Shin splints are common in people who run or jog. Activities where you run or jump on hard surfaces, such as basketball or tennis, can also lead to shin splints. They can also be caused by training too hard or running in shoes that are worn out.