Understanding Your Creatinine Levels

A creatinine test measures the level of creatinine in your blood and urine. Creatinine is a waste product made when your muscle tissue breaks down. Your kidneys normally filter creatinine from your blood before removing it through your urine. However, if your kidneys aren’t working properly, it can cause high creatinine levels in your blood and low levels in your urine.

What Is Creatinine?

Creatinine is a normal waste product your body produces when muscle tissue breaks down. Your kidneys filter creatinine from your blood before removing it through your urine. If your kidneys aren’t working properly, it can cause high creatinine levels in your blood and low levels in your urine.

What Is A Creatinine Test?

A creatinine test measures the level of creatinine in your blood or urine.

Why would I need a creatinine test?

You may need a creatinine test to check how well your kidneys are working.

What are the types of creatinine tests?

There are several types of creatinine tests, including:

• Creatinine clearance — Compares creatinine levels in your blood and your 24-hour urine sample to determine how much creatinine has traveled from your blood to your urine.
• Serum (blood) creatinine — Shows how well your kidneys are filtering creatinine, a waste product, from your blood.
• Urine albumin-to-creatinine ratio (uACR) — Looks for high levels of a protein called albumin in your urine.
• Urine protein-to-creatinine ratio (uPCR) — Looks for high levels of all types of protein in your urine, not just albumin.

How Do You Interpret Creatinine Test Results?

Normal blood creatinine levels may be different depending on each person’s:

• Activity level
• Age
• Diet
• Muscle mass

Generally, a normal blood creatinine level for men is 0.7 to 1.3 mg/dL and 0.6 to 1.1 mg/dL for women.

What level of creatinine is concerning?

If you have high or low blood creatinine levels, you should talk to your healthcare provider.

Your healthcare provider will tell you what your normal levels should be and whether your creatinine test results are normal, high, or low.

What should my creatinine be for my age?

Normal blood creatinine levels tend to increase with age. When you receive your blood creatinine test results, your lab may include an adjusted recommended range.

What Does It Mean When Your Creatinine Level Is High?

High creatinine levels in your blood may be a sign of kidney disease.

However, high blood creatinine levels can also be a sign of:

• Dehydration.
• Muscle problems.
• Pregnancy-related conditions such as eclampsia or preeclampsia.
• Urinary tract blockage.

Low blood creatinine levels can be caused by liver disease, decreased muscle mass, or malnutrition.

If your healthcare provider suspects kidney disease, they may order another test called estimated glomerular filtration rate (eGFR). This test shows how efficiently your kidneys function based on age, creatinine level, and sex.

Why choose UPMC for kidney care?

When you choose UPMC for kidney care, you will receive:

• Access to world-class nephrology expertise — Our world-renowned experts treat the full spectrum of kidney diseases using the latest diagnostic and treatment techniques.
• A full range of treatment options — We'll work with you to develop a treatment plan that slows the progression of your disease as much as possible and improves your quality of life.
• Multidisciplinary care — If you need advanced kidney treatment, we partner with special dialysis clinics, experts in supportive care, and kidney transplant surgeons.

By UPMC Editorial Staff. Last reviewed on 2025-04-24 by Pooja Amarapurkar, MD.