A phosphate in urine test measures the amount of phosphate in your urine. Phosphate is an electrically charged particle that contains the mineral phosphorous. Phosphorous works together with the mineral calcium to build strong bones and teeth. It also plays an essential role in nerve function and how the body uses energy.
Your kidneys control the amount of phosphate in your body. If you have a problem with your kidneys, it can affect your phosphate levels. Phosphate levels that are too low or too high can be a sign of a serious health problem.
Other names: phosphorous test, P, PO4
A phosphate in urine test may be used to:
Most people with high phosphate levels don’t have any symptoms.
You may need a phosphate in urine test if you have symptoms of a low phosphate level. These include:
You may also need a phosphate in urine test if you’ve had abnormal results on a calcium test. Calcium and phosphate work together, so problems with calcium levels can mean problems with phosphate levels as well. Calcium testing in blood and/or urine is often part of a routine checkup.
You’ll need to collect all your urine during a 24-hour period. This is called a 24-hour urine sample test. Your health care provider or a laboratory professional will give you a container to collect your urine in and instructions on how to collect and store your samples. A 24-hour urine sample test generally includes the following steps:
You don’t need any special preparations for a phosphate in urine test. Be sure to carefully follow all the instructions for providing a 24-hour urine sample.
There is no known risk to having a phosphate in urine test.
The terms phosphate and phosphorous can mean the same thing in test results. So your results may show phosphorous levels rather than phosphate levels.
If your test shows you have high phosphate/phosphorous levels, it may mean you have:
If your test shows you have low phosphate/phosphorous levels, it may mean you have:
If your phosphate/phosphorous levels are not normal, it doesn’t necessarily mean you have a medical condition needing treatment. Other factors, such as your diet, can affect your results. Also, children often have higher phosphate levels because their bones are still growing. If you have questions about your results, talk to your health care provider.
Phosphate is sometimes tested in the blood instead of urine.