Urine concentration test

For this test, some or all of the specific gravity of urine , urine electrolytes , and urine osmolality are measured before and after one or more of the following: Water loading. Drinking large amounts of water or receiving fluids through a vein. Water deprivation. Not drinking fluids for a certain amount of time.…

Eat your normal diet for several days before the test. Your provider will give you instructions for water loading or water deprivation. Your provider will ask you to temporarily stop any medicines that may affect the test results. Be sure to tell your provider about all the medicines you take, including dextran and…

The test involves only normal urination. There is no discomfort.

This test is most often done if your provider suspects central diabetes insipidus , a condition where there is an abnormality with ADH that regulates the concentration of the urine. The test can help tell that disease from nephrogenic diabetes insipidus , a condition where there is an abnormality in the kidney that…

In general, normal values for specific gravity are as follows: 1.005 to 1.030 (normal specific gravity) 1.001 after drinking excessive amounts of water More than 1.030 after avoiding fluids 50 percent rise in specific gravity after receiving ADH Normal value ranges may vary slightly among different laboratories. Some…

Increased urine concentration may be due to conditions, such as: Glucose (a type of sugar) in the urine Heart failure Loss of body fluids (dehydration) from diarrhea, vomiting, or excessive sweating Narrowing of the kidney artery (renal arterial stenosis) SIADH Decreased urine concentration may indicate: Diabetes…

There are no risks with this test.

Navarro D, Fonseca NM, Garigali G, Fogazzi GB. Urinalysis. In: Johnson RJ, Floege J, Tonelli M, eds. Comprehensive Clinical Nephrology . 7th ed. Philadelphia, PA: Elsevier; 2024:chap 4. Riley RS, McPherson RA. Basic examination of urine. In: McPherson RA, Pincus MR, eds. Henry's Clinical Diagnosis and Management by…