Saturday, February, 11, 2012

Urine concentration test

Table of Contents

Alternative Names

Water loading test; Water deprivation test


Normal Values

In general, normal values are as follows:

  • 1.0002 to 1.030 (normal specific gravity)
  • 1.001 after drinking excessive amounts of water
  • More than 1.030 after avoiding fluids
  • Concentrated after receiving ADH

Note: 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

Increased urine concentration may indicate:

  • Dehydration
  • Diarrhea that leads to dehydration
  • Excessive sweating that leads to dehydration
  • Glycosuria
  • Heart failure (related to decreased blood flow to the kidneys)
  • Renal arterial stenosis
  • Syndrome of inappropriate antidiuretic hormone secretion (SIADH)
  • Vomiting
  • Water restriction

Decreased urine concentration may indicate:

  • Excessive fluid intake
  • Diabetes insipidus
  • Renal failure (loss of ability to reabsorb water)
  • Pyelonephritis

Additional conditions under which the test may be performed:

  • Complicated UTI (pyelonephritis)
  • Nephrogenic diabetes insipidus

Review Date: 08/07/2009
Reviewed By: David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine. Also reviewed by David Zieve, MD, MHA, Medical Director, A.D.A.M., Inc.

A.D.A.M., Inc. is accredited by URAC, also known as the American Accreditation HealthCare Commission (www.urac.org)