In many cases of blunt renal trauma, a small tear in its capsule will cause only a little local bleeding and, with that, the formation of a localised blood clot, a perinephric haematoma. On other occasions, there may be a deeper tear in the kidney which shows itself by way of haematuria. In severe injuries, the degree of bleeding, both into the loin and by way of haematuria into the urinary tract proper, may be heavy – even, on occasion, life threatening. In that situation, the patient will have an obvious loin swelling due to bleeding into the loin. There will be a progressive bruising, though actual skin discolouration may not be present in the early phase. More importantly, and particularly if the patient has associated haematuria, the internal bleeding will lead to oligaemic shock, as shown by a falling blood pressure and a rising pulse. In severe trauma, the vascular pedicle of the kidney can be torn off, leaving the kidney without any circulation and hence without viability.