DefinitionThe sodium urine test measures the amount of salt (sodium) in a urine sample.Sodium can also be measured in a blood sample.See also: Sodium - blood testAlternative NamesUrinary 24 hours sodium; Urine Na+How the test is performedThis test may be done using a random urine sample or a 24-hour urine collection.If a 24-hour urine sample is needed:On day 1, urinate into the toilet when you get up in the morning.Afterwards, collect all urine in a special container for the next 24 hours.On day 2, urinate into the container when you get up in the morning.Cap the container. Keep it in the refrigerator or a cool place during the collection period.Label the container with your name, the date, the time of completion, and return it as instructed.For an infant, thoroughly wash the area around t