Site Map

Osmolality urine test

The osmolality urine test measures the concentration of particles in urine.

Osmolality can also be measured using a blood test.

Images

Osmolality test
Female urinary tract
Male urinary tract

Presentation

Osmolality urine - series

How the Test is Performed

A clean-catch urine sample is needed. The clean-catch method is used to prevent germs from the penis or vagina from getting into a urine sample. To collect your urine, the health care provider may give you a special clean-catch kit that contains a cleansing solution and sterile wipes. Follow instructions exactly.

How to Prepare for the Test

Your provider may tell you that you need to limit your fluid intake 12 to 14 hours before the test.

Your provider will ask you to temporarily stop taking any medicines that may affect the test results. Be sure to tell your provider about all the medicines you take, including dextran and sucrose. DO NOT stop taking any medicine before talking to your provider.

Other things can also affect the test results. Tell your provider if you recently:

How the Test will Feel

The test involves normal urination. There is no discomfort.

Why the Test is Performed

This test helps check your body's water balance and urine concentration.

Osmolality is a more exact measurement of urine concentration than the urine specific gravity test.

Normal Results

Normal values are as follows:

Normal value ranges may vary slightly among different laboratories. Some labs use different measurements or test different samples. Talk to your provider about the meaning of your specific test results.

What Abnormal Results Mean

Abnormal results are indicated as follows:

Higher than normal measurements may indicate:

Lower than normal measurements may indicate:

Risks

There are no risks with this test.

Related Information

Osmolality blood test
Heart failure
Shock
Antidiuretic hormone blood test
Acute tubular necrosis
Low blood sodium

References

Berl T, Sands JM. Disorders of water metabolism. In: Feehally J, Floege J, Tonelli M, Johnson RJ, eds. Comprehensive Clinical Nephrology. 6th ed. Philadelphia, PA: Elsevier; 2019:chap 8.

Oh MS, Briefel G. Evaluation of renal function, water, electrolytes, and acid-base balance. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by Laboratory Methods. 23rd ed. St Louis, MO: Elsevier; 2017:chap 14.

BACK TO TOP

Review Date: 7/7/2019  

Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA. Also reviewed by David Zieve, MD, MHA, Medical Director, Brenda Conaway, Editorial Director, and the A.D.A.M. Editorial team.

ADAM Quality Logo

A.D.A.M., Inc. is accredited by URAC, for Health Content Provider (www.urac.org). URAC's accreditation program is an independent audit to verify that A.D.A.M. follows rigorous standards of quality and accountability. 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 policy, editorial process and privacy policy. A.D.A.M. is also a founding member of Hi-Ethics. This site complies with the HONcode standard for trustworthy health information: verify here.

The information provided herein should not be used during any medical emergency or for the diagnosis or treatment of any medical condition. A licensed medical professional should be consulted for diagnosis and treatment of any and all medical conditions. Links to other sites are provided for information only -- they do not constitute endorsements of those other sites. © 1997- 2021 A.D.A.M., a business unit of Ebix, Inc. Any duplication or distribution of the information contained herein is strictly prohibited.

A.D.A.M. content is best viewed in IE9 or above, Firefox and Google Chrome browser.