What is a significant consideration when testing urine for specific gravity?

When testing urine for specific gravity, the time of day the urine is collected is a significant consideration because the concentration of urine can vary throughout the day based on hydration status and dietary intake. Typically, urine is more concentrated in the morning after a night of fasting, resulting in a higher specific gravity reading, while urine collected later in the day may be more diluted due to fluid intake, leading to a lower specific gravity.

Understanding the timing of urine collection is important for accurate assessment of kidney function and hydration status, as variations in specific gravity can provide insights into a person's fluid balance, renal concentrating ability, or potential underlying health issues. This context enhances the reliability of the test results and helps guide clinical decisions.