What does a 'timed specimen' for urine collection refer to?

A 'timed specimen' for urine collection specifically refers to a sample that is collected over a designated period. This type of collection is important for various laboratory tests, as it allows for the assessment of substances that may fluctuate in concentration throughout the day or after certain activities. By collecting urine over a specified timeframe—such as 24 hours—healthcare providers can obtain a comprehensive overview of a patient’s renal function or the levels of specific metabolites, hormones, or other substances that may be present in urine.

Collecting a specimen immediately after voiding, collecting only in the morning, or collecting a specimen after eating do not capture the full range of substances that might be present in urine over time, rendering them inadequate for the purpose that a timed specimen serves. Therefore, the concept of capturing urine over a defined duration is key to obtaining accurate and meaningful diagnostic information.