Alternative Names urine creatinine - spot collection
Definition This test measures the amount of creatinine in the urine. Creatinine is produced in the muscles and filtered by the kidneys. The amount of creatinine in the urine, then, is an indication of kidney function. It is most often used to check kidney function.
Who is a candidate for the test? This test may also be ordered to check a person's intake of fluid or high protein foods such as meat. It also detects muscle damage or degeneration, nerve damage from diabetes mellitus, or other disorders of the endocrine system. It provides clues about damage or blockages within the kidney, bladder or other parts of the urinary system.
How is the test performed? Either a 24-hour urine sample or a "spot" sample is required.
For a spot collection, the person starts urinating and collects a small sample in a container. The container is sealed and given to the doctor.
For a 24-hour urine sample, the person should follow the specific instructions of the doctor. In general, this schedule is followed:
Day 1: The person urinates upon arising as usual. The person does not collect that sample. Then, the individual collects all urine produced for the next 24 hours in a special container.
Day 2: First thing in the morning, the person urinates into the container again. Then the individual covers it and refrigerates it the sample can be brought to the doctor.
What is involved in preparation for the test? The person should request specific instructions from the doctor.
What do the test results mean? Normal values for creatinine in urine are:
myasthenia gravis, or a nervous system disorder that causes progressive muscle weakness and fatigue
a diet high in meat
Author: Reviewer: eknowhow Medical Review Panel Editor: Dr John Hearne Last Updated: 19/05/2005 Contributors Potential conflict of interest information for reviewers available on request
