Having no white blood cells in the urine is considered a normal finding, according to MedlinePlus. High numbers of white blood cells in urine generally indicate infection or inflammation somewhere in the urinary tract or contamination of the sample, explains Lab Tests Online.Continue Reading
White blood cells are found on a urinalysis during the microscopic evaluation, according to Lab Tests Online. This evaluation is done on urine sediment, which is a concentration of substances at the bottom of a tube after urine is put through a centrifuge. The microscopic evaluation typically determines the presence of red blood cells, epithelial cells, bacteria, casts and crystals. In a normal specimen, bacteria are not present, and only a few epithelial cells, red blood cells and clear, or hyaline, casts may be present. Crystals are considered normal if they are comprised of solutes that are normally found in urine, such as amorphous urates, crystalline uric acid, calcium oxalates and calcium carbonate.
Urinalysis also includes a visual examination, which reveals the urine's color, clarity and concentration, according to MedlinePlus. A chemical evaluation is performed by using test strips to check for certain substances, such as protein, glucose, ketones, nitrite and bilirubin, states Lab Tests Online. These substances are not typically found in the urine of healthy people.Learn more about Medical Ranges & Levels