Health Encyclopedia

Sodium - urine

Definition

The sodium urine test measures the amount of salt (sodium) in a urine sample.

Sodium can also be measured in a blood sample.

Alternative Names

Urinary 24 hours sodium; Urine Na+

How the test is performed

This test may be done using a random urine sample or a 24-hour urine collection.

If a 24-hour urine sample is needed:

On day 1, urinate into the toilet when you get up in the morning.
Afterwards, collect all urine in a special container for the next 24 hours.
On day 2, urinate into the container when you get up in the morning.
Cap the container. Keep it in the refrigerator or a cool place during the collection period.
Label the container with your name, the date, the time of completion, and return it as instructed.

For an infant, thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on the infant. For males, place the entire penis in the bag and attach the adhesive to the skin. For females, place the bag over the labia. Diaper as usual over the secured bag.

This procedure may take a couple of attempts -- lively infants can move the bag, causing the urine to be absorbed by the diaper. Check the infant frequently and change the bag after the infant has urinated into it. Drain the urine from the bag into the container provided by your health care provider.

Deliver it to the laboratory or your health care provider as soon as possible upon completion.

How to prepare for the test

Your health care provider will instruct you, if necessary, to discontinue drugs that may interfere with the test.

Drugs that can increase test measurements include:

Certain antibiotics
Certain corticosteroids
Diuretics
Prostaglandins

Drugs that can decrease test measurements include:

Nonsteroidal anti-inflammatory drugs (NSAIDs)

If a 24-hour urine collection is being taken from an infant, a couple of extra collection bags may be necessary.

How the test will feel

The test involves only normal urination, and there is no discomfort.

Why the test is performed

The test is often used to determine your hydration status and the kidney's ability to conserve or remove sodium.

Additional conditions under which the test may be performed:

Acute tubular necrosis
Hepatorenal syndrome
Medullary cystic kidney disease
Glomerulonephritis
Prerenal azotemia
Uncontrolled high blood pressure (hypertension)

Normal Values

Normal values are generally 15 to 250 milliequivalents per liter per day (mEq/L/day), depending on how much fluid and salt you consume. Normal value ranges may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

What abnormal results mean

Greater than normal urine sodium levels may be caused by too much salt in the diet.

Lower than normal urine sodium levels may indicate:

What the risks are

There are no risks.

Special considerations

Too little or too much sodium in the diet may affect test results.

Review Date:10/22/2007
Reviewed By:Robert Mushnick, M.D., Clinical Assistant Professor, Department of Nephrology, SUNY Downstate Health Center, Brooklyn, NY. Review provided by VeriMed Healthcare Network.

ADAM Quality A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org). URAC's accreditation program is the first of its kind, requiring compliance with 53 standards of quality and accountability, verified by independent audit. A.D.A.M. is among the first to achieve this important distinction for online health information and services. Learn more about A.D.A.M.'s editorial process. A.D.A.M. is also a founding member of Hi-Ethics (www.hiethics.com) and subscribes to the principles of the Health on the Net Foundation (www.hon.ch).

The Agency for Health Care Administration (Agency) and this website do not claim the information on, or referred to by, this site is error free. This site may include links to websites of other government agencies or private groups. Our Agency and this website do not control such sites and are not responsible for their content. Reference to or links to any other group, product, service, or information does not mean our Agency or this website approves of that group, product, service, or information.

Additionally, while health information provided through this website may be a valuable resource for the public, it is not designed to offer medical advice. Talk with your doctor about medical care questions you may have.