You should suspect a kidney injury anytime the patient presents with

A hematoma in the flank locale. A hematoma is a confined accumulation of blood outside the veins, due to either malady or injury including damage or surgery and may include blood proceeding to leak from broken vessels. A hematoma is at first in fluid shape spread among the tissues incorporating into sacs between tissues where it might coagulate and harden before blood is reabsorbed into veins. An ecchymosis is a hematoma of the skin bigger than 10mm.

Idont really understand