If a person lost one kidney, would they have symptoms?

This is a question for all you medical jellies, that’s arisen from a short fantasy story I’m writing. It’s a fantasy/historical setting so medical care is limited. The main character has been wounded in battle. He survives, but it occurs to me that because of where the wound is, he may well have lost a kidney and not know it. Heck, he probably doesn’t even know he has kidneys. Would there be any signs or symptoms of such a loss?