Pain under the left rib cage can be a sign of a heart attack, which is a medical emergency. An enlarged or ruptured spleen, which may result from trauma, can cause sharp pain. Kidney infections can ...

Floating rib injuries are caused, in part, by a vulnerability in human anatomy. The rib cage, which is made up of 12 pairs of ribs, doesn't fully attach to other bones in the same way at all points.