|Test Performed Stat
The urine concentration test shows changes early in chronic renal disease.
Diabetes insipidus, characterized by abnormal function of antidiuretic hormone (ADH), presents a relatively dilute urine despite the need to conserve water. Low specific gravity may also occur in patients with glomerulonephritis, pyelonephritis, and various renal anomalies.
Specific gravity is high in patients with diabetes mellitus, adrenal insufficiency, hepatic disease, congestive cardiac failure; and when there has been excessive loss of water, as with sweating, fever, vomiting and diarrhea. High amounts of glucose and protein increase the specific gravity of urine by .004 and .003 for each 1% of the respective constituents.