Creatinine (urine)

What does the "Creatinine (urine)" test show?«

Creatinine is a metabolic product that is formed mainly in muscle tissue and excreted from the body by the kidneys. Determination of creatinine in urine allows you to estimate its excretion and can be used together with other laboratory indicators to assess kidney function.

The study can be performed both separately and as part of a comprehensive examination of kidney function. The amount of creatinine in the urine depends not only on kidney function, but also on muscle mass, nutrition, and other factors.

When is the test prescribed?

The study may be recommended by a doctor for:

• suspected renal dysfunction;
• diseases of the urinary system;
• monitoring of kidney status during treatment;
• assessment of daily creatinine excretion;
• performing calculations related to kidney function;
• comprehensive examination in case of changes in creatinine levels in the blood.

How to properly collect daily urine

If the study is prescribed based on daily urine:

• the first morning portion of urine must be released into the toilet and not to collect;
• all subsequent portions during the day, night and the morning portion of the next day should be collected in one container;
• if the collection started at 6:00, the first portion at 6:00 is not collected, and all subsequent portions are collected until 6:00 the next day inclusive;
• capacity to store at temperature +4…+8 °C, in a cool place, protected from sunlight;
• after collection, mix all urine thoroughly;
• measure and indicate total daily urine volume;
• to indicate volume of fluid consumed during the day;
• cast 40–50 ml mixed urine into a separate sterile container;
• deliver the sample to the laboratory within 2 hours.

To the laboratory «"MediLab+"» daily urine must be delivered without added preservatives.

What can affect the result?

The level of creatinine in the urine can be affected by muscle mass, physical activity, dietary habits, the amount of fluid consumed, and some medications.

It is important to collect all of your urine throughout the day, as missing even one portion can affect the accuracy of your daily creatinine clearance calculation.

It is not recommended to change your diet or stop taking prescribed medications before the test. You should inform your doctor about any medications and supplements you are taking.

How is the result evaluated?

The result of the analysis is evaluated taking into account age, gender, muscle mass, daily urine volume, and other laboratory parameters.

To assess kidney function, the doctor may additionally prescribe: blood creatinine, GFR calculation, urea and other tests.

The creatinine level in the urine alone does not allow to establish a specific disease. The interpretation of the result is carried out by the doctor in combination with other data.