The pain in your shins when you run is likely caused by a condition called shin splints, or medial tibial stress syndrome. This occurs due to overuse or repetitive stress on the shin bone (tibia) and the surrounding muscles and tendons. The pain arises because of inflammation and microtrauma to the bone lining or the muscles pulling on the tibia. Common reasons include increasing running mileage or intensity too quickly, running on hard or uneven surfaces, poor running form such as overstriding, and inadequate recovery between workouts. Rest, proper training balance, icing, and wearing appropriate footwear can help manage and prevent shin splints. If the pain is sharp, localized, or worsens over time, it could indicate a stress fracture, which requires medical attention. Regular stretching, proper running technique, and gradual progression in training intensity are key to avoiding shin pain when running.