Zimnitsky urine test (24-hour, in portions)
Zimnitsky test · urine concentration test · 24-hour urine in portions · kidney concentration test
For 24 hours, you collect urine into 8 separate jars, one every 3 hours. This test is common in Russia and nearby countries. The lab checks how your kidneys concentrate urine by day and by night.
To check how your kidneys work, if you pee often at night, or for swelling or thirst.
⏱ Duration: collection takes 24 hours; results usually come in 1 to 2 days
Be sure to tell your doctor
How to prepare
- Jars. You need 8 clean containers. Label each with a time: 9:00, 12:00, 15:00, 18:00, 21:00, 0:00, 3:00, 6:00, or as the lab tells you.
- Food and drink. Eat and drink as usual. Write down how much you drank in 24 hours, if your doctor asked.
- Medicines. Do not stop them on your own. Tell your doctor about water pills in advance. They will decide.
- Alarm. Set an alarm for the night portions.
What to bring
- The 8 jars of urine
- Your fluid log, if asked
- Your test request form
- Your ID
How it goes
- In the morning at about 6:00, pee into the toilet. You do not keep this urine
- After that, every 3 hours, pee into the jar with the right time
- If you need to pee again within those 3 hours, use the same jar
- If a jar fills up, take an extra one and label it with the same time
- Collect the last portion at 6:00 the next morning
- Keep the jars in the fridge and take them to the lab in the morning
What you'll feel
- Nothing unpleasant, but you need to watch the time, including at night
Afterwards
- Results usually come in 1 to 2 days
- Your doctor will explain the results
Common questions
What if I did not need to pee during one time slot?
Leave that jar empty and still bring it to the lab.
Should I drink extra water?
No. Drink as usual. Otherwise the result will not be accurate.