Creatinine

Creatinine is a waste product from muscle metabolism. It is filtered by the kidneys and is a key marker of kidney function.

The concentration of creatinine in the blood.

To assess kidney function, often alongside eGFR calculation.

Results for creatinine are reported as a numerical value with an associated unit of measurement. The unit depends on the laboratory and the assay method used. When comparing results from different labs, always confirm the units match before drawing conclusions about a trend.

This biomarker may be reported in any of the following units:

Reference ranges vary from laboratory to laboratory. They are established by each lab based on its own testing method, equipment, and the population it serves. A result that appears outside the reference range on one lab's report may fall within range on another's.

Ranges can also differ by age, biological sex, and other individual factors. Some labs report multiple reference ranges for different patient groups. Always interpret your result against the reference range printed on the specific lab report, not against a general value you find online.

A result flagged as “out of range” does not by itself indicate a medical condition. Discuss any results that concern you with a qualified healthcare professional.

Muscle mass, diet, medications, and hydration can affect creatinine.

A single Creatinine result is a snapshot. Tracking it over time is where the real insight lives. TrackMyMarkers lets you record every result from every lab, automatically aligning units so you can see genuine trends across months and years.

Longitudinal tracking helps you and your healthcare professional spot gradual shifts, see how lifestyle changes correlate with your numbers, and bring clear, organized data to every appointment.

Consider bringing these questions to your next appointment:

• How has my creatinine changed?
• What is my eGFR?

References and source citations will be added here. In the meantime, the information on this page is intended for general educational purposes and should not replace professional medical advice.