In principle, urine in the bladder is sterile. This means that it does not contain any bacteria or other organisms. However, bacteria can enter the urethra upstream and cause a urinary tract infection.

Urine is generally pale yellow and relatively clear; however, the color, quantity, concentration, and content of substances in urine will vary slightly from person to person due to different components. Urine test indicators include glucose, protein, bilirubin, red blood cells, white blood cells, crystals, and bacteria.

Urine is the result of the physiological activity of the kidneys, kidney diseases will be expressed by changes in the properties of urine. Therefore, urine analysis plays a very important role in diagnosing kidney and urinary diseases.

Urine test is one of the extremely important health check-up and assessment activities, indicated for general health check-up and screening for many other diseases. Each parameter in the urine test has a certain meaning to reflect the health status of the body.

In general, a small number of epithelial cells in the urine is not a cause for concern. However, an abnormal increase in the number of these cells in the urine can indicate a warning sign of certain medical conditions, such as a urinary tract infection, kidney disease, liver disease, or cancer.