What condition does high specific gravity of urine suggest?

High specific gravity of urine indicates that the urine is more concentrated than normal, suggesting that there is a higher than typical level of solutes present. This concentration often occurs in conditions where the body is attempting to conserve water, such as dehydration. When the body is dehydrated, it retains more water, leading to concentrated urine—thus resulting in a high specific gravity measurement.

In contrast, kidney failure typically results in an inability of the kidneys to concentrate urine, which would lead to lower specific gravity, not higher. Overhydration dilutes the urine, causing a decrease in specific gravity. Although certain infections can lead to changes in urine characteristics, they do not typically cause high specific gravity, as the body is more likely to produce dilute urine in response to infection or fever, which are associated with increased overall fluid loss. Thus, high specific gravity is most accurately linked to dehydration.