The phosphate urine test measures the amount of
phosphate in a sample of urine collected over 24 hours
(24-hour urine test). Phosphate is a charged particle (ion) that contains the
mineral phosphorus. The body needs phosphorus to build
and repair bones and teeth, help nerves function, and make muscles contract.
Most (about 85%) of the phosphorus contained in phosphate is found in bones.
The rest of it is stored in tissues throughout the body.
The
kidneys help control the amount of phosphate in the
body. Extra phosphate is filtered by the kidneys and passes out of the body in
the urine. If there is not enough phosphate, less is found in the urine. A high
level of phosphate in the urine may be caused by a kidney problem. High levels
also may be caused by eating a meal high in phosphorus or by an overactive
parathyroid gland.
Calcium and phosphate levels are often measured at the
same time.
Many medicines can change the results of this test. Be sure to tell
your doctor about all the nonprescription and prescription medicines you
take.
Talk to your doctor about any concerns you have regarding the need
for the test, its risks, how it will be done, or what the results may mean.
To help you understand the importance of this test, fill out the
medical test information form(What is a PDF document?).
Urine phosphate is usually measured in a sample taken from all the
urine produced in a 24-hour period.
To collect your urine for 24 hours:
You start collecting your urine in the morning.
When you first get up, empty your bladder but do not save this urine. Write
down the time that you urinated to mark the beginning of your 24-hour
collection period.
For the next 24 hours, collect all your urine.
Your doctor's office or lab will usually provide you with a large container
that holds about 1 gal (4 L).
The container has a small amount of preservative in it. Urinate into a small,
clean container and then pour the urine into the large container. Do not touch
the inside of the container with your fingers.
Keep the large
container in the refrigerator for the 24 hours.
Empty your bladder
for the final time at or just before the end of the 24-hour period. Add this
urine to the large container and record the time.
Do not get toilet
paper, pubic hair, stool (feces), menstrual blood, or other foreign matter in
the urine sample.
The phosphate urine test measures the amount of
phosphate in a sample of urine collected over 24 hours
(24-hour urine test). Phosphate is a charged particle (ion) that contains the
mineral phosphorus.
Normal
Normal values may vary from lab to lab. Results are usually
available in 1 to 2 days.
Many conditions can change phosphate levels. Your doctor will talk
with you about any abnormal results that may be related to your symptoms and
past health.
Phosphate may also be measured in the blood.
For more information, see the medical test
Phosphate in Blood.
Results of a test to
measure phosphate in urine are seldom useful on their own. They should always
be interpreted along with the results of other tests.
The loss of
too much phosphate into the urine may cause conditions that damage the bones,
such as
rickets or osteomalacia.
This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.This information does not replace the advice of a doctor. Healthwise disclaims any warranty or liability for your use of this information. Your use of this information means that you agree to the Terms of Use. How this information was developed to help you make better health decisions.
