What is the Creatinine (Urine) test?

The Creatinine (Urine) test measures the concentration of creatinine present in a urine sample. Creatinine is a metabolic by-product of muscle activity and is excreted by the kidneys.

According to the laboratory documentation, urine creatinine is commonly used as a supportive biochemical marker and as a reference value in urine-based testing. It helps contextualise and interpret other urine analytes by accounting for urine concentration.

The test is performed on a random urine (RU) sample, as listed in the laboratory guide.

Why do I need a urine creatinine test?

Urine concentration varies significantly depending on hydration, timing, and fluid intake. Measuring urine creatinine allows laboratories and clinicians to understand whether a urine sample is dilute or concentrated.

This test is frequently requested when interpreting other urine-based investigations or when assessing renal excretion patterns.

You may need a urine creatinine test if you:

• Are undergoing urine-based biochemical testing
• Need reliable interpretation of urine results
• Are completing panels that include urine markers
• Require assessment of renal excretion
• Are monitoring results over time using urine samples
• Have variable hydration levels affecting urine tests

Benefits of the Creatinine (Urine) test

• Supports interpretation of urine tests
  Provides context for urine analyte concentrations.
• Reflects renal excretion of creatinine
  Indicates how creatinine is cleared into urine.
• Accounts for urine concentration variability
  Helps identify dilute or concentrated samples.
• Widely used laboratory marker
  Standard component of urine biochemistry.
• Non-invasive testing method
  Requires only a urine sample.
• Useful in repeat monitoring
  Allows comparison between samples over time.
• Supports accuracy of urine panels
  Improves reliability of urine-based investigations.
• Simple and clinically recognised
  Included in accredited laboratory test menus.

Step by step – how the test works

You have two UK-wide testing options:

1. Clinic appointment
   Attend your nearest UK clinic and provide a urine sample on site.
2. At-home testing (£60 extra)
   Collect your urine sample at home following provided instructions, without attending a clinic.

Your sample is analysed by an accredited laboratory in line with the lab guide documentation.

Your results explained

Low urine creatinine levels

Usually indicate dilute urine, often due to high fluid intake or timing of sample collection.

Typical laboratory interpretation:

• Lower than expected concentration for a random urine sample

Normal urine creatinine levels

Suggest appropriate urine concentration and reliable sample quality.

Typical laboratory interpretation:

• Within laboratory reference interval

High urine creatinine levels

Usually reflect concentrated urine, commonly due to reduced fluid intake or dehydration.

Typical laboratory interpretation:

• Above laboratory reference interval

Exact reference ranges depend on laboratory reporting standards and sample type.