An osmolality urine test is performed to measure the concentration of particles in urine. Greater than normal results may indicate conditions such as Addison's disease, congestive heart failure or shock. Lower-than-normal measurements may indicate aldosteronism, diabetes insipidus, excess fluid intake, renal tubular necrosis or severe pyelonephritis.
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.