Cr
Creatinine, serum
High
1.8mg·dL⁻¹Ref 0.7–1.3 mg·dL⁻¹
Z +5.33↑ Bad

The card shows an example result of 1.8 mg·dL⁻¹, which is 5.33 SD above the mean.

What it measures

Creatinine comes from the normal breakdown of muscle creatine and is cleared by the kidneys. When filtering falls, it builds up.

Reference range

FieldValue
AbbreviationCr
GroupKidney and protein
Unitmg·dL⁻¹
Healthy range0.7–1.3
Mean1
SD0.15
Direction↑ Bad — a raised value is the concern.

The mean is (low + high) / 2 and the SD is (high − low) / 4, so the healthy range covers Z from −2 to +2.

Reading the result

  • High — Suggests reduced kidney function. High muscle mass, a large meat meal, or dehydration can also raise it.
  • Low — Not a concern. Low values can reflect low muscle mass.

Notes

  • Ranges differ for men and women.
  • Creatine supplements raise it.
  • This page is general information, not medical advice. Discuss results with a clinician.