Sodium in Blood: About This Test

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What is it?

A sodium test checks how much sodium is in your blood. Sodium helps your body keep the right mix of water and minerals.

  • High sodium levels can be caused by being dehydrated, having kidney disease, or having a condition called diabetes insipidus that makes it hard to balance the water level in the body.
  • Low sodium levels most often occur as a side effect of taking medicines that make you urinate more, such as diuretics. Severe diarrhea or vomiting or heavy sweating may also cause low sodium levels.

Why is this test done?

This test is usually done to check the water and electrolyte balance of the body.

How can you prepare for the test?

  • In general, you don’t need to prepare before having this test. Your doctor may give you some specific instructions.

What happens during the test?

  • A health professional takes a sample of your blood.

What else should you know about the test?

  • Your results will include an explanation of what a "normal" result is. This is called a "reference range." It is just a guide. Your doctor will evaluate your results based on your health and other factors. This means that a value that falls outside the normal values listed may still be normal for you.
  • Other minerals, such as potassium, calcium, chloride, magnesium, and phosphate, may be checked in a blood sample at the same time as a blood test for sodium.

How long does the test take?

  • The 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 or nurse call line 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?

Go to https://www.healthwise.net/patientEd

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Current as of: October 14, 2016