Urine analysis is a group of chemical and microscopic tests that detect the byproducts of normal and abnormal metabolism, cells, cellular fragments, and bacteria in urine. It is used to diagnose conditions and diseases such as urinary tract infection, kidney infection, kidney stones, inflammation of the kidneys, or screen for progression of conditions such as diabetes and high blood pressure. In patients with acute or chronic conditions, it may also be ordered at intervals as a rapid method to help monitor organ function, status, and response to treatment. The microscopic examination is done to look at cells, urine crystals, mucus, and other substances, and to identify any bacteria or other microorganisms that might be present. The specific gravity test reveals how concentrated or dilute the urine is. The presence of casts and cellular debris usually suggest an injury to the kidney from an inflammation or lack of blood flow to the kidneys. A high count of red blood cells in the urine can indicate infection, trauma, tumors, and kidney stones. Evidence of white blood cells or bacteria in the urine is considered abnormal and may suggest a urinary tract infection such as, bladder infection (cystitis), or infection of kidney (pyelonephritis).
It is important to examine fresh specimens, otherwise cells and casts may disintegrate or distort with bacterial infections.