<P> Perform ultrasound examination of the kidney to rule out obstructive processes . </P> <P> The mechanisms causing oliguria can be categorized globally in three different categories: </P> <Ul> <Li> Prerenal: in response to hypoperfusion of the kidney (e.g. as a result of dehydration by poor oral intake, cardiogenic shock, diarrhea, G6PD deficiency, massive bleeding or sepsis) </Li> <Li> Renal: due to kidney damage (severe hypoperfusion, rhabdomyolysis, medication) </Li> <Li> Postrenal: as a consequence of obstruction of the urine flow (e.g. enlarged prostate, tumour compression urinary outflow, expanding hematoma or fluid collection) </Li> </Ul> <Li> Prerenal: in response to hypoperfusion of the kidney (e.g. as a result of dehydration by poor oral intake, cardiogenic shock, diarrhea, G6PD deficiency, massive bleeding or sepsis) </Li>

A decrease in the normal amount of urine is called oliguria