Costochondritis is inflammation of the cartilage that connects the ribs to the breastbone (sternum). This cartilage forms the costosternal joints, which allow the rib cage to move during breathing. When the cartilage becomes inflamed, it can cause sharp or aching pain in the chest, typically on the left side but sometimes on the right. The pain may worsen with deep breaths, coughing, or certain movements of the upper body, because these actions cause the rib cage to expand and move.
The condition can occur after physical strain, repetitive movements, minor trauma to the chest, or sometimes without a clear cause. People with costochondritis often experience tenderness when pressure is applied to the affected rib joints near the sternum. Although the pain can feel similar to heart-related chest pain, costochondritis is a musculoskeletal condition involving the chest wall rather than the heart or lungs.
