What does a decreased specific gravity (less than 1.005) indicate?

A decreased specific gravity, which falls below 1.005, typically indicates a higher concentration of water in the urine relative to solutes. This is often associated with increased hydration or the kidneys' inability to concentrate urine effectively.

When an individual is well-hydrated, the kidneys excrete a larger volume of more dilute urine, resulting in a lower specific gravity. This is a normal physiological response to high fluid intake, reflecting the body’s regulation of water balance.

In the context of renal disease, particularly in its early stages, the kidneys may start losing their ability to concentrate urine due to damage to the filtering units (nephrons). Conditions like glomerulonephritis can impair kidney function, leading to similar urine characteristics. Therefore, the decreased specific gravity can suggest renal issues, including glomerulonephritis, but it may also indicate increased hydration, offering a multifactorial interpretation of the results.

The correct answer identifies a condition that often manifests with this finding, highlighting the relationship between specific gravity and kidney function.