The 24-hour urinalysis is an analysis of urine collected over 24 hours to assess kidney function, very useful for identifying to monitor kidney diseases.
This test is mainly indicated to measure kidney function or to evaluate the amount of proteins or other substances in the urine, such as sodium, calcium, oxalate or uric acid, for example, as a way to identify diseases of the kidneys and urinary tract.
To perform this test, it is necessary to collect all the urine in a proper container for a period of 24 hours, and it must be taken to the laboratory that will analyze the values. Learn about other urine tests that exist and how to collect them.
What is it for
The 24-hour urine test is used to assess kidney function to detect possible kidney changes by determining the amount of some substances in the urine such as:
- Creatinine Clearance that assesses the filtration rate of the kidneys. Know what it is for and when the creatinine clearance test is indicated; Proteins, including Albumin; Sodium; Calcium; Uric acid; Citrate; Oxalate; Potassium.
Other substances such as ammonia, urea, magnesium and phosphate can also be quantified in this test.
In this way, 24-hour urine can help the doctor to identify problems such as kidney failure, diseases of the renal tubules, causes of stones in the urinary tract or nephritis, which is a set of diseases that cause inflammation of the renal glomeruli. Better understand what nephritis is and what it can cause.
In pregnancy, this test is usually used to determine the presence of proteins in the pregnant woman's urine for the diagnosis of pre-eclampsia, which is a complication that arises in pregnancy, in which the pregnant woman develops hypertension, fluid retention and protein loss due to urine.
How to harvest the exam
To perform the 24-hour urine test, the individual must follow the following steps:
- Search the laboratory's own container The next day, in the morning, after waking up, urinate in the toilet, ignoring the first urine of the day; Note the exact time of urination you made in the toilet; After you have urinated in the toilet, collect all day and night urine in the container; The last urine to be collected in the container must be at the same time as the urine of the previous day. that you did in the toilet, with a tolerance of 10 minutes.
For example, if the individual urinated at 8 am, urine collection should end at exactly 8 am the next day or at least at 7:50 am and at most at 8:10 am.
Care during urine collection
During 24-hour urine collection, it is necessary to take certain precautions such as:
- If you are going to evacuate, you should not urinate in the toilet because all the urine must be placed in the container; If you are going to take a shower, you cannot urinate in the bath; If you leave the house, you have to take the container with you or you cannot urinate until you return home.; You cannot have a 24-hour menstrual urine test.
Between urine collections, the container should be in a cool place, preferably refrigerated. When the collection is finished, the container should be taken to the laboratory as soon as possible.
Reference values
Some of the 24-hour urine test reference values are:
- Creatinine clearance between 80 and 120 ml / min, which may be decreased in kidney failure. Understand what kidney failure is and how to treat it; Albumin: less than 30 mg / 24 hours; Total proteins: less than 150 mg / 24 hours; Calcium: without diet up to 280 mg / 24h and with diet 60 to 180 mg / 24h.
These values can vary according to the age, sex, health conditions of the person and the laboratory that performs the exam, so they should always be evaluated by the doctor, who will indicate the need for treatment.
The 24-hour urine test due to the difficulty in collecting and the frequent errors that can occur, has been less and less requested in medical practice, being replaced by other more recent tests, such as mathematical formulas that can be done after a simple urine test..
