The location of the painful costochondritis is usually located in the second to fourth rib cartilage, and sometimes down to the rib arch. Although theoretically, all areas where rib cartilage is present can be inflamed and cause pain, the above mentioned areas are the most common in clinical practice. Patients can locate these areas in the following manner: First, they should first feel down their trachea, and when they reach the chest they can feel a long strip of bone that is parallel to the anterior midline, which is the sternum. Secondly, there is a very obvious corner in the upper middle section of the sternum, feel along the corner to the left and right, and the part connected to it is the second rib cartilage, along the second rib cartilage can be followed down to the fourth rib cartilage, and then continue to feel down to the eighth rib cartilage to the tenth rib cartilage, which is connected in the forefront into an arch, this part is called the rib arch. The above mentioned areas are the most common sites of costochondritis and are usually located in the area in front of the armpit and behind the sternum.