What would cause a decreased specific gravity in urine?

A decreased specific gravity in urine typically indicates that the urine is more dilute, which usually occurs when there is an increased volume of water relative to solutes. Increased fluid intake leads to greater hydration and consequently results in the production of more dilute urine. When the body is well-hydrated, the kidneys excrete excess water to maintain homeostasis, which lowers the specific gravity because there are fewer solutes compared to the total volume of urine.

High specific gravity would be seen in cases of dehydration, where the body concentrates urine to conserve water, and also during shock due to reduced renal perfusion. Increased excretion of urine solutes might raise specific gravity rather than decrease it. Therefore, increased fluid intake is a clear contributor to decreased specific gravity in urine.