Urinalysis interpretation: how to squeeze out the maximum information from a small sample.

The urinalysis is an essential part of the diagnostic evaluation for all urinary and many metabolic diseases. Its assessment includes evaluation of physical characteristics (color, clarity, and volume), biochemical parameters (urine pH, blood, glucose, ketones, bilirubin, urobilinogen, and protein) and microscopic sediment evaluation (RBC, WBC, organisms, epithelial cells, crystals, and casts). Many of these parameters are influenced by collection method and therefore, it is essential to interpret accordingly. Knowledge of factors that can interfere with the accuracy of some test results can decrease improper interpretation. When all of these parameters are evaluated in combination with clinical signs, physical examination, thorough history and other laboratory tests, a diagnosis will often be attained.