What is creatinine?

Written by

Lauren Dobischok
30 June, 2022

Medically checked article All HOMED-IQ content is reviewed by medical specialists

The kidneys play an important role in the body, such as in the production of hormones, maintaining an optimal fluid balance, and filtering waste. With Homed-IQ’s Liver and Kidney Function Test you can check several biomarkers that indicate overall kidney health, including your creatinine value.

What is creatinine?

Creatinine is a waste product made by the muscles. As it is produced, creatinine enters your bloodstream and is filtered and broken down in the kidneys. A small amount of creatinine is excreted in the urine. This creates a balanced level in the blood, which is determined by the speed of creatinine production in the muscles and breakdown/excretion by the kidneys (De Prostaatkliniek).

What does creatinine value indicate?

Your creatinine value provides insight into the functioning of the kidneys. There is a constant concentration of creatinine in the blood. Therefore, the creatinine value is an excellent indicator to determine whether the kidneys are functioning properly. One’s blood creatinine value determines the amount of waste products in the blood. With this value it is possible to estimate the amount of blood that the kidneys filter per minute (eGFR) (Health and Science, 2018).

What is a normal creatinine value?

A normal blood creatinine value differs from person to person, with men usually having a higher creatinine level than women. This is because men have more skeletal muscle. Likewise, a person with more muscle has a higher creatinine value than a person with less muscle. A normal value is generally between 50 and 110 micromol/liter (Dutch Association for Clinical Chemistry and Laboratory Medicine, 2011), whereby the following reference values ​​apply for men and women:

  • 50 – 100 micromol/liter for women
  • 60 – 110 micromol/liter for men

What does low creatinine mean?

A creatinine value is considered normal when it is below 100 micromol/liter for women and below 110 micromol/liter for men. Creatinine levels may be low due to liver problems, aging, or low muscle mass (Dutch Journal of Medicine, 1990).

What does high creatinine mean?

A creatinine level that is too high can be an indication that the kidneys are not functioning optimally. In that case, waste products are less efficiently filtered out of the blood and excreted through the kidneys, so blood creatinine rises. Incidentally, it is not always the case that a high creatinine level means that the kidneys are not functioning properly. In bodybuilders who have a large muscle mass, an elevated creatinine level does not necessarily mean that the kidneys are not functioning properly. If your test results indicate your creatinine level is high, discuss with your doctor for possible causes or whether additional testing is needed.

Testing Creatinine Levels 

Testing creatinine levels provides a snapshot of your kidney function. With Homed-IQ’s Liver and Kidney Function Test, you can measure your creatine levels and other important values from home. This blood and urine test provides insight into the following values: ALT, AST, GammaGT, Bilirubin, Albumin, Creatinine, eGFR and Alkaline Phosphatase. In this way, you get as complete a picture as possible of both your kidneys and liver health. The advantage of testing creatinine with a home test is that you do not have to go to the doctor. The analysis of the creatinine value and other biomarkers takes place in a certified laboratory.

The causes of a creatinine level that is too high

A creatinine value that is too high can have various causes. For example, a sports injury that caused muscle damage, or kidney stones. Reduced kidney function can also be caused by prostate problems, bacterial infections that result in kidney inflammation, or complications due to diabetes. It is also possible that the use of certain drugs reduces kidney function.

Are there any diseases related to elevated creatinine?

There are several diseases related to elevated creatinine, such as diabetes and high blood pressure. Additionally, there are several kidney diseases that can lead to kidney failure, which causes the blood creatinine level to rise.

The consequences of a creatinine level that is too high

Symptoms of high creatinine are not always noticeable. In the early stages of kidney or liver damage, there are usually no symptoms. At a later stage you may suffer from:

  • Itch
  • Nausea
  • Fatigue
  • Lowered immunity

How do I lower my creatinine level?

Blood creatinine can be lowered in various ways. For example, it is possible to address contributing health conditions such as high blood pressure. In that case, it is important to eliminate salt from your diet as much as possible. Your doctor can also prescribe medication to lower blood pressure. In addition to salt, it is also advisable to limit proteins with high blood pressure. Quitting smoking and weight loss (if you are overweight) can also help lower creatinine. In addition, it is advisable not to use painkillers such as NSAIDs if your creatinine is high, as they have a negative effect on kidney function (Kidney Foundation).

Tip: also read our article “What are kidney biomarkers and what can they tell me about my health?

About the author

Lauren Dobischok

Lauren is a health scientist and science communicator currently living in the Netherlands. Originally from Canada, she completed a Research Master’s in Health Sciences at the Netherlands Institute of Health Sciences at Erasmus University Rotterdam (NIHES) with a specialisation in epidemiology. Prior to her master’s degree, she completed a Bachelor’s degree in Health Sciences at Simon Fraser University. With a background in public health, her goal is to create accurate scientific content that is easy to understand and empowers people to make informed decisions. Within Homed-IQ, Lauren works as a Product Developer and Content Lead, working closely with physicians and scientists on medical devices for Homed-IQ’s new products and written communications.