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What Do High Creatinine Levels Mean?


Creatinine is a waste product that is produced by your muscles. It is typically removed through the kidneys. Healthy kidneys filter creatinine out of your blood, and it leaves your body through urine. Your doctors can measure the amount of creatinine in your blood and in your urine to get an idea of how well your kidneys are working. This measurement is called creatinine clearance. 

Having high creatinine levels probably isn’t harmful on its own, though it can be a marker of other health conditions—including chronic kidney disease (CKD). A serum creatinine blood test, along with factors such as age, weight, and medical history, can help doctors understand how well your kidneys are functioning and whether there may be an issue.

What does a creatinine level test involve?

Sometimes creatinine levels are tested over a 24-hour period. You’ll be asked to collect all of your urine over that time frame and bring it in to your doctor. The lab will test the amount of creatinine in your urine, and then compare that to the amount of creatinine in your blood. This shows your doctor how much waste is being filtered out of your body—and how your kidneys are performing.

Sometimes your care team needs answers faster. If you’re experiencing acute kidney failure, it’s not effective to take a whole day to collect urine. Plus, most doctors don’t want to put you through the inconvenience of collecting urine for a whole day. That’s when doctors use a simple blood test and a formula to estimate your creatinine clearance.


High creatinine levels can be a sign to focus on your kidney health. While permanent kidney damage can’t be reversed, careful management can help slow the progression of any further kidney damage.

Creatinine and GFR

One important calculation your doctor will perform is to determine your estimated glomerular filtration rate (eGFR). Your glomerular filtration rate is a measurement of how well your kidneys are working to clean your blood. Your doctor will calculate your eGFR using your serum creatinine blood test results and factoring in your age, weight, body size, ethnicity and gender. If you are diagnosed with CKD, your eGFR indicates which of the 5 stages of CKD you’re in. You can use our on line GFR calculator to calculate your eGFR, once you have the serum creatinine blood test results from your doctor.

Your doctor may want to compare your creatinine levels over time because there are many factors that can affect results in the short term. A long-term view of creatinine levels can offer a more accurate measurement of overall kidney function.

What are the symptoms of high creatinine levels?


Like proteinuria, a high creatine level is more an indication of a potential health problem, rather than a problem itself. If your creatine level increase is caused by a kidney issues, you may experience related symptoms. Kidney conditions often cause bladder and fluid retention issues. If your kidneys aren’t working well enough to remove toxins and waste from your body, you could notice a wide range of symptoms, including:

  • Nausea
  • Chest Pain
  • Muscle Cramps
  • Vomiting
  • Fatigue
  • Changes in urination frequency and appearance
  • High blood pressure
  • Swelling or fluid retention
  • Itchiness

What can I do about high creatinine?


If you have a kidney condition and high creatinine levels, it’s important to take them seriously and take steps to protect your kidney health. Here are some things your doctor may recommend:

  • Follow a healthy lifestyle.
  • Make changes to your diet to avoid stress on your kidneys.
  • Cut back on strenuous exercise.
  • Avoid creatine supplements.
  • Discuss any medications you’re taking, including over-the-counter medicine. 

To help prevent damage to your kidneys, it’s also important that you manage any other health conditions that can affect kidney function, like high blood pressure or diabetes. If you’re diagnosed with CKD, your doctor may also prescribe medications. If your tests indicate kidney failure, your doctor will talk to you about treatment options, like transplant or dialysis.



If your lab tests have shown high creatinine levels, discuss your results with your care team. You may need to repeat your creatinine blood test and undergo further testing to help determine your high creatinine causes. Taking action as soon as possible will help you feel better and take control of your health.

High creatinine and protein

  • If you’re not on dialysis: be careful not to get too much protein in your diet. Remember, the body uses creatine in muscle metabolism, and that creatine becomes a waste product of that process. Protein fuels that process, which means that too much of it will create extra creatinine and other wastes. If your kidneys aren’t working well to filter toxins and waste, you don’t want to add to their burden. Talk to your doctor about how much protein you should be getting in your diet. 

  • If you’re already on dialysis: your body may actually need more protein. Dialysis removes amino acids that are the building blocks of albumin, a protein that’s vital to your health, so you may need to eat more protein to replace it. Your doctor and renal dietician will prescribe the right amount and types of foods and drinks for your best health—and help you create a diet that best fits your health needs.


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