In Vikings, in the first attack on Paris, Ragnar jumps from the tower, hits his back on one of the siege towers and then hits the pile of dead bodies. After this, it is shown that he is injured, but it's never said what kind of injury he really has.
From what we see, it's not the spine (he can walk), but rather something internal like liver or kidney damage. Later on, he's seen having bloody urine and vomiting. His coughing seems to be a symptom of a lung injury.
Can someone give more hints or a better diagnosis?