Kidney (renal) trauma is when the kidney is hurt by an outside force. There are two types of trauma Blunt and Penetrating Trauma.
The best sign of blunt kidney injury is blood in the urine (“hematuria”). Sometimes the blood can be seen with the naked eye. Other times, it can only be seen through a microscope.
Blunt trauma kidney injuries may show no outside signs. Or bruises may be seen over the back or abdomen where the kidneys are.
Penetrating kidney trauma may be suspected when there’s a wound from a knife, bullet or other object that has pierced the skin. But sometimes these wounds may be small or hard to find. Also, sometimes the skin wound is far away from the kidney.