Cells found in Urine
You may find the following cells when looking at a urine sample under the microscope.
Transitional Epithelial cells
These cells originate from the urinary tract system, which consists of the renal pelvis, ureter, bladder, and urethra. The normal range for transitional epithelial cells in urine is 0 to 1 cell per high-powered field, and a higher number of cells suggests inflammation of the urinary tract system.
Squamous epithelial cells
These cells are found in the external genital area and the lower urinary tract, which consists of the bladder, urethra, and, in men, the prostate. The normal range for squamous cells in urine is 0 to 15 cells per high-powered field. An increased presence of squamous cells can indicate the patient did not collect the urine sample midstream. Female urine samples often contain an increased number of squamous epithelial cells that originate from vaginal secretions. A large number of squamous cells can give a false positive for white blood cells, also called leukocytes, on the urine dipstick test.
White blood cells (leukocytes)
The normal range for white blood cells in urine is 0 to 4 cells per high-powered field. More cells than this expected range could indicate a urinary tract infection, inflammation of the urinary tract system, or a health condition related to the kidneys or bladder.
Red blood cells (erythrocytes)
There are two types of red blood cells with different shapes, eumorphic and dysmorphic cells, as shown in Figure 1. The normal range for eumorphic red blood cells in urine is 0 to 1 cell per high-powered field. More cells than this expected range could indicate kidney and urinary tract problems, such as a urinary tract infection. However, it could be due to menstrual bleeding.
The appearance of eumorphic red blood cells depends on the pH of the urine. In a pH of 6, the cells are round and disc-shaped. If the pH is greater than 6, the cells lose their disc shape; if the pH is less than 6, the cells gain little thorns. The pH of urine is related to the health of the individual, for example, if the patient's urine is high, then they might have a urinary tract infection.
Figure 1: Different types of cells under the microscope. A) Squamous cell. B) Leukocyte. C) Transitional Epithelial cell. D) Eumorphic erythrocyte at pH 6. E) Eumorphic erythrocyte at pH greater than 6.