24-Hour Urine Collection
What is a 24-hour urine collection?
A 24-hour urine collection is a
simple lab test that measures what’s in your urine. The test is used to check kidney
function. A 24-hour urine collection is done by collecting your urine in a special
container over a full 24-hour period. The container must be kept cool until the urine
returned to the lab.
Urine is made up of water and
dissolved chemicals, such as sodium and potassium. It also contains urea. This is
when protein breaks down. And it contains creatinine, which is formed from muscle
breakdown. Normally, urine contains certain amounts of these waste products. It may
sign of a certain disease or condition if these amounts are not within a normal range.
Or if other substances are present.
Why might I need a 24-hour urine collection?
A 24-hour urine collection helps
diagnose kidney problems. It is often done to see how much creatinine clears through
kidneys. It’s also done to measure protein, hormones, minerals, and other chemical
Conditions that can cause kidney disease include:
nephropathy. This happens when someone has uncontrolled diabetes. It causes
high levels of protein (albumin) in the urine and can lead to kidney damage.
- High blood
pressure. Abnormally high blood pressure can lead to lasting (permanent)
nephritis. Lupus is an autoimmune disease where the immune system
attacks the kidneys and damages them.
- Frequent urinary tract infections.
- Prolonged urinary tract blockage.
- Alport syndrome. This health problem causes
vision and hearing problems, as well as progressive scarring of the kidneys. The
syndrome is passed down through families.
syndrome. This health problem has several different causes. Symptoms include protein in the
urine, low protein in the blood, high cholesterol levels, and tissue swelling.
- Polycystic kidney disease. This health
problem causes the growth of many fluid-filled cysts in the kidneys. This makes the
kidneys larger. Over time, it takes over and destroys working kidney tissue.
- Interstitial nephritis or
pyelonephritis. This is an inflammation in the small structures in the kidney. It’s often caused
for preeclampsia in pregnancy. Preeclampsia is a dangerous health problem that sometimes occurs in
pregnancy. It causes high blood pressure and can lead to organ failure.
- Kidney stones (nephrolithiasis). Kidney stones
form because of an imbalance of minerals, salts and water in the urine.
There may be other reasons for your healthcare provider to recommend 24-hour urine
What are the risks of a 24-hour urine collection?
A 24-hour urine collection is a
safe, easy test. People can collect urine on their own.
Certain factors may affect the
accuracy of a 24-hour urine collection. These include:
- Forgetting to collect some of your urine
- Going beyond the 24-hour collection period and collecting too much urine
- Losing urine from the specimen container through spilling
- Not keeping urine cold while collecting it
- Acute stress
- Vigorous exercise
- Certain foods, such as coffee, tea, cocoa, bananas, citrus fruits, and vanilla
There may be other risks depending
on your specific health problems. Be sure to discuss any concerns with your healthcare
provider before the collection.
How do I get ready for a 24-hour urine collection?
- Your healthcare provider will explain the procedure and you can ask questions.
- Make sure you understand if you need
to stay away from certain foods while collecting your urine.
- You will be given large containers to store your urine and a container to urinate
into. Make sure you know how to use them. Have a cold place to store the urine while
you’re collecting it. For instance, a refrigerator or in a cooler on ice.
- You may be told to start the collection at a specific time.
- If possible, choose a 24-hour period when you will be at home so you do not have to
transport your urine.
- If you are pregnant or think you may be, tell your healthcare provider.
- Make sure your provider has a list of
all medicines (prescription and over-the-counter), herbs, vitamins, and supplements
that you are taking.
Based on your health condition,
your healthcare provider may request other specific preparation.
What happens during a 24-hour urine collection?
A 24-hour urine collection may be
done on an outpatient basis. This means you go home the same day. Or it may be done
during a hospital stay. Procedures may vary depending on your condition and your
healthcare provider's practices.
Generally, a 24-hour urine collection follows this process:
- You will be given 1 or more containers
for collecting and storing your urine. A brown plastic container is typically used.
special pan that fits in the toilet or a urinal may be used to collect the urine.
will need to transfer the urine from the collecting container to the storage
container. You will need to keep it cold.
- The 24-hour collection may start at
any time during the day after you urinate. But your healthcare provider may tell you
when to start. It is common to start the collection the first thing in the morning.
It is important to collect all urine in the following 24-hour period.
- Don't save the urine from your first
time urinating. Flush this first specimen, but note the time. This is the start time
of the 24-hour collection.
- All urine, after the first flushed specimen, must be saved, stored, and kept cold.
This means keeping it either on ice or in a refrigerator for the next 24 hours.
- Try to urinate again at the same time, 24 hours after the start time, to finish the
collection process. If you can’t urinate at this time, it is OK.
- Once the urine collection has been completed, the urine containers need to be taken
to the lab as soon as possible. If you are doing the urine collection at home, you
will be given instructions on how and where to take it.
- Depending on your specific health
problem, you may be asked to repeat the collection over several days.
What happens after a 24-hour urine collection?
There is no special type of care
after a 24-hour urine collection. But your healthcare provider may give you other
instructions after the procedure, depending on your particular situation.
Before you agree to the test or the procedure make sure you know:
- The name of the test or procedure
- The reason you are having the test or procedure
- What results to expect and what they mean
- The risks and benefits of the test or procedure
- What the possible side effects or complications are
- When and where you are to have the test or procedure
- Who will do the test or procedure and what that person’s qualifications are
- What would happen if you did not have the test or procedure
- Any alternative tests or procedures to think about
- When and how will you get the results
- Who to call after the test or procedure if you have questions or problems
- How much will you have to pay for the test or procedure