Waste product of muscle creatine metabolism. Filtered freely by the glomerulus with minimal secretion/reabsorption. Rises when GFR falls significantly (>50% nephron loss).
| Sex | Age | Range | Notes |
|---|---|---|---|
| Female | ≥ 18 yrs | 44 – 97 | Adult female |
| Male | ≥ 18 yrs | 62 – 115 | Adult male |
⚠ Clinical Note
Reference ranges are indicative. Always interpret results in the context of the individual patient and local laboratory reference intervals, which may vary.