• 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.

In infants, thoroughly wash the area around the urethra. Open a urine collection bag (a plastic bag with an adhesive paper on one end), and place it on the infant. For males, the entire penis can be placed in the bag and the adhesive attached to the skin. For females, the bag is placed over the labia. Diaper as usual over the secured bag. This procedure may take a couple of attempts -- lively infants can displace the bag, causing the specimen to be absorbed by the diaper. The infant should be checked frequently and the bag changed after the infant has urinated into the bag. The urine is drained into the container for transport to the laboratory.

Deliver it to the laboratory or your health care provider as soon as possible upon completion.

Cl- is the major extracellular negative ion in the body. Its main purpose is to maintain electrical neutrality, mostly as a counter-ion to sodium. It often accompanies sodium losses and excesses. It also affects acid-base balance. That is, as CO2 (carbon dioxide) increases, bicarbonate moves from inside the cells to the outside. Then, to maintain electrical neutrality, more chloride tends to enter cells.

Because of its relationship with other electrolytes, urinary chloride results can be used to help assess volume status, salt intake, causes of hypokalemia, and to aid in the diagnosis of renal tubular acidosis.

Increased urine chloride excretion may be caused by:

• Increased salt intake
• Postmenstrual diuresis
• Pharmacologic diuresis
• Salt-losing nephritis
• Adrenocortical insufficiency

• Decreased salt intake
• Adrenocortical hyperfunction
• Extrarenal fluid loss (such as diarrhea, vomiting, sweating, and gastric suction)
• Salt retention