Creatinine: What It Is and What Your Results Mean

Name: Creatinine: What It Is and What Your Results Mean
Creator: Ernestas K.

Bottom line: Creatinine is a kidney function marker. Normal is 0.5-1.3 mg/dL. Elevated levels may indicate declining kidney function.

What Is Creatinine?

Creatinine is a waste product produced by your muscles during normal activity. It is filtered out of your blood by your kidneys and excreted in urine. Because creatinine production is relatively constant, blood creatinine levels serve as a reliable indicator of kidney function.

When kidneys are not filtering efficiently, creatinine builds up in the blood. Elevated creatinine is one of the earliest detectable signs of declining kidney function, often appearing before any symptoms develop.

Creatinine levels are also used to calculate eGFR (estimated glomerular filtration rate), which is the gold standard for assessing how well your kidneys are working overall.

Creatinine Reference Ranges

Classification	Range (mg/dL)
Low (Possible Muscle Loss)	Below 1.5
Normal (Female)	0.5 - 1.1
Normal (Male)	0.7 - 1.2
Mildly Elevated	1.3 - 2.0
Elevated	2.1 - 5.0
Very High — Possible Kidney Failure	5.1 - 20.0

What Affects Your Creatinine Levels?

Kidney function and disease
Muscle mass (more muscle = higher baseline creatinine)
Diet, particularly high protein intake and creatine supplements
Hydration status
Certain medications including NSAIDs and some antibiotics
Age (kidney function naturally declines with age)

When to Get Tested

Creatinine is part of standard metabolic panels done during annual physicals. More frequent testing if you have diabetes, high blood pressure, or a family history of kidney disease, as these are the leading causes of kidney damage.

Look Up Your Creatinine Result

Select your value below to see a detailed breakdown of what it means:

Low (Possible Muscle Loss)

Creatinine 0.3 mg/dL Creatinine 0.4 mg/dL Creatinine 0.5 mg/dL

Normal (Female)

Creatinine 0.6 mg/dL Creatinine 0.7 mg/dL Creatinine 0.8 mg/dL Creatinine 0.9 mg/dL Creatinine 1.0 mg/dL Creatinine 1.1 mg/dL

Normal (Male)

Creatinine 1.2 mg/dL

Mildly Elevated

Creatinine 1.3 mg/dL Creatinine 1.4 mg/dL Creatinine 1.5 mg/dL Creatinine 1.6 mg/dL Creatinine 1.7 mg/dL Creatinine 1.8 mg/dL Creatinine 1.9 mg/dL Creatinine 2.0 mg/dL

Elevated

Creatinine 2.2 mg/dL Creatinine 2.5 mg/dL Creatinine 2.8 mg/dL Creatinine 3.0 mg/dL Creatinine 3.5 mg/dL Creatinine 4.0 mg/dL Creatinine 4.5 mg/dL Creatinine 5.0 mg/dL

Very High — Possible Kidney Failure

Creatinine 6.0 mg/dL Creatinine 7.0 mg/dL Creatinine 8.0 mg/dL Creatinine 9.0 mg/dL Creatinine 10.0 mg/dL Creatinine 12.0 mg/dL Creatinine 15.0 mg/dL

Read the Full Blood Test Guide

Frequently Asked Questions

What is a normal creatinine level?

For women, 0.5-1.1 mg/dL is normal. For men, 0.7-1.3 mg/dL is normal. Levels vary based on muscle mass, so athletes may have slightly higher baseline levels.

Does high creatinine always mean kidney disease?

Not always. Temporary elevations can occur from dehydration, high-protein meals, intense exercise, or creatine supplements. Persistent elevation, however, warrants further kidney function testing.

How can I protect my kidney function?

Stay hydrated, manage blood pressure and blood sugar, limit NSAID use, avoid excessive protein supplements, and get regular checkups if you have risk factors.

Ernestas K.

Clinical Research Writer