How a Urinalysis Is Done
In most cases, urine is collected in a clean container, then a small plastic strip
that has patches of chemicals on it (the dipstick) is placed in the urine. The patches
change color to indicate things like the presence of white blood cells or glucose.
Next, the doctor or laboratory technologist also usually examines the same urine
sample under a microscope to check for other substances that indicate different conditions.
If the dipstick test or the microscopic test shows white blood cells, red blood
cells, or bacteria (possible signs of a kidney or bladder infection), the doctor
may send the urine to a lab for a urine culture to identify the bacteria that
may be causing the infection.
Getting a urine sample. It can be difficult to get urine samples
from kids to test for a possible infection. That's because the skin around the urinary
opening (urethra) normally is home to some of the same bacteria that cause UTIs.
If these bacteria contaminate the urine, the doctors might not be able to use the
sample to tell if there is a true infection or not.
To avoid this, the skin surrounding the urinary opening has to be cleaned and rinsed
immediately before the urine is collected. In this "clean-catch" method, the patient
(or parent) cleans the skin, the child then urinates, stops momentarily (if the child
is old enough to cooperate), then urinates again into the collection container. Catching
the urine in "midstream" is the goal.
In some cases (for instance, if a child is not toilet trained), the doctor or nurse
will insert a catheter (a narrow, soft tube) through the urinary tract opening into
the bladder to get the urine sample. In certain situations, a sterile bag can be placed
around a baby’s diaper area to collect a urine sample.
If you have any questions about urine tests, talk with your doctor.
Date reviewed: March 2015