Does high urine specific gravity affect urine protein testing?
Jun 24, 2025
Source: Cainiu Health
Dr. Shen Yonghua
Introduction
When urine is significantly diluted by water, the urine specific gravity decreases, which may lead to an underestimation of urinary protein levels. The originally detected proteinuria (plus sign) might appear reduced. Conversely, if the urine is overly concentrated, resulting in increased specific gravity, it may cause an overestimation of urinary protein, and the originally detected proteinuria (plus sign) might appear increased. Therefore, high urine specific gravity may affect the accuracy of urine protein testing.
Generally speaking, high urine specific gravity may affect urine protein testing. The specific analysis is as follows:
Urine specific gravity is an important parameter in urine tests, reflecting the kidney's ability to concentrate and dilute urine. The level of urine specific gravity can be influenced by multiple factors, including water intake, dietary composition, and kidney function status. In urine protein testing, changes in urine specific gravity may impact the test results.
When urine is significantly diluted by high fluid intake, the urine specific gravity decreases, which might lead to underestimation of urine protein levels, potentially reducing the reported proteinuria grade. Conversely, if the urine is overly concentrated, resulting in elevated specific gravity, it may lead to overestimation of urine protein levels, potentially increasing the reported proteinuria grade. Therefore, abnormal urine specific gravity may affect the qualitative results of urine protein testing, leading to inaccuracies in the reported proteinuria grades.
In daily life, if urine specific gravity remains consistently high, timely medical evaluation at a hospital is recommended.
