This is a specialized test to measure the total amount of copper your body excretes in your urine over a full day. It is the primary diagnostic tool for Wilson's disease, a rare genetic condition where copper builds up in vital organs like the liver and brain. This test is also essential for monitoring the effectiveness of treatment for this condition. The test requires you to collect all your urine over a 24-hour period in a specific, clean-catch container. This comprehensive, 24-hour analysis provides the definitive, clear-cut answers your doctor needs to diagnose and manage this specific condition.