Costochondritis (kos-toe-kon-DRY-tis) is an inflammation of the cartilage that connects a rib to the breastbone, called the sternum. Pain caused by costochondritis might be like that of a heart attack or other heart conditions. Costochondritis is sometimes called chest wall pain syndrome, costosternal syndrome or costosternal chondrodynia. Sometimes, there is swelling with the pain, which is a condition called Tietze syndrome. What causes costochondritis is unclear. Treatment focuses on easing the pain while waiting for the condition to improve on its own. This can take several weeks or more.