What is costochondritis characterized by?

Costochondritis is characterized by inflammation of the cartilage that connects the ribs to the sternum, which is known as the costal cartilage. This condition usually presents as localized pain in the chest area, often mistaken for cardiac pain or other serious conditions. The inflammation in the costal cartilage can lead to tenderness and discomfort, particularly with movement or palpation of the chest wall.

The other options do not accurately describe costochondritis. While inflammation of muscles (option A) could cause pain, it is not the defining feature of costochondritis. An infection of the chest wall (option C) represents a different pathology, typically associated with conditions like pneumonia or abscess formation, which is not the case in costochondritis. Lastly, degeneration of the spine (option D) refers to spinal issues and does not pertain to the inflammation of costal cartilage, which is specific to costochondritis.