Costochondritis is an inflammation of the cartilage that connects the ribs to the breastbone, known as the sternum. This condition can cause sharp chest pain, which may worsen with certain movements or deep breaths. It is often mistaken for heart-related issues, but it is generally harmless. The exact cause of costochondritis is often unclear, but it can result from physical strain, injury, or repetitive activities. Treatment typically includes rest, pain relief medications, and sometimes physical therapy. Most people recover fully without any long-term effects.