Costochondritis is a diffuse pain syndrome characterized by pain, tenderness and inflammation of the costal cartilage, which connects the ribs to the sternum (breastbone). Pain is experienced in the front of the chest, and it typically goes away on its own.

Because multiple joints connecting the cartilage to the ribs or sternum are usually involved, the pain often occurs from different areas, although it may radiate widely throughout the chest. Costochondritis is not usually associated with swelling but may be associated with arthritis.

Costochondritis is the most common cause of chest pain from the chest wall (not the heart). Though it may affect any age group, it occurs most frequently in adults over age 40.

When swelling does occur, the condition is referred to as Tietze syndrome. In Tietze syndrome, localized, painful, bulbous swelling occurs on the cartilaginous joints of the chest. Generally, the costochondral joints (between the rib and the cartilage) of the second and third ribs are affected, but the costosternal (between the cartilage and sternum) and sternoclavicular (between the sternum and clavicle, or collarbone) joints may also be involved. There is no pus or other discharge associated with this swelling, and the swelling is typically unilateral (occurring on only one side).

Tietze syndrome may result in sharper, more sudden pain. It is a rare condition that primarily affects young adults under the age of 40 years, but it may occur in all age groups, including children.