Urine is usually hypotonic with large amounts of sodium chloride, potassium, phosphate and magnesium 
Urine Output > 125 - 200mL/hour after relief of obstruction for at least 3 consecutive hours
Urine Osmolarity > 250mosm/kg
Post-obstructive diuresis
Osmotic diuresis
Contrast-induced nephropathy
Hyperglycemia
Dialysis-associated hypotension
Mannitol
Dehydration 
Drugs: diuretics, caffeine, acetazolamide, lithium