Medical Laboratory Science Practice Test 2026 – Complete Prep for MLS Module 1

Examining urine sediment focuses on the formed elements you can visualize under the microscope, not just chemical tests or color. The elements most commonly linked to pathology are red blood cells, white blood cells, bacteria, crystals, and casts. Red blood cells in the sediment point to bleeding anywhere along the urinary tract or kidney. White blood cells signal inflammation or infection within the urinary tract or kidneys. Bacteria seen in the sediment confirms bacteriuria and supports a diagnosis of infection. Crystals form when urine is supersaturated with certain solutes and can indicate stone risk or metabolic disorders, while casts are tubular structures formed in the kidney; their presence and type reflect various renal tubular conditions, with some casts (like granular or epithelial casts) pointing to tubular injury and others (like broad casts) suggesting chronic renal disease. Protein and glucose or relying on urine color or pH alone don’t provide the same specific, morphological evidence of pathology that sediment elements do.