Phosphate in Blood: About This Test

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What is it?

A phosphate test measures the amount of phosphate in your blood. Your body needs this mineral to build and repair bones and teeth, help nerves function, and make muscles contract.

The kidneys help control the amount of phosphate in your blood. A high level of phosphate is usually caused by a kidney problem.

Why is this test done?

This test may be done to check phosphate levels if you have kidney disease or bone disease. It helps find problems with certain glands, such as the parathyroid glands. The test is also used to find a cause for abnormal vitamin D levels.

How do you prepare for the test?

Tell your doctor ALL the medicines, vitamins, supplements, and herbal remedies you take. Some may affect the test results. Your doctor will tell you if you should stop taking any of them before the test and how soon to do it.

How is the test done?

A health professional uses a needle to take a blood sample, usually from the arm.

How long does the test take?

This test will take a few minutes.

What happens after the test?

  • You will probably be able to go home right away.
  • You can go back to your usual activities right away.

Follow-up care is a key part of your treatment and safety. Be sure to make and go to all appointments, and call your doctor if you are having problems. It's also a good idea to keep a list of the medicines you take. Ask your doctor when you can expect to have your test results.

Where can you learn more?

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The Health Encyclopedia contains general health information. Not all treatments or services described are covered benefits for Kaiser Permanente members or offered as services by Kaiser Permanente. For a list of covered benefits, please refer to your Evidence of Coverage or Summary Plan Description. For recommended treatments, please consult with your health care provider.