I have a pain under my right ribcage and having difficulty breathing?

Get evaluated. . The most common cause of pleuritic chest pain in a younger person without signs of a lung infection is costochodritis, or an inflammation or injury to the ribs. The pain often causes a labored breathing pattern known as splinting. However, make sure you are seen so that atypical chest pain related to the heart, or an infection of the lung, is not missed. Make sure you are evaluated!