Low Creatinine Levels: What Do the Results Mean?

Creatinine is a waste product that comes from the breakdown of proteins from the food you eat, as well as the normal breakdown of muscle in your body. The kidneys remove creatinine from your blood and send it into your urine so it leaves the body.

Creatinine can be measured through a blood or urine test. The purpose of a creatinine test is to see how well your kidneys are filtering your blood, including removing creatinine, which can help healthcare providers monitor the health of your kidneys and aid in diagnosing kidney disease. 

High amounts of creatinine in the blood may be a sign of a kidney problem, though a variety of factors may be at play that may not be related to kidney health. Similarly, low creatinine levels can be due to various factors, from dietary choices to muscle mass and more.

This article discusses what constitutes low creatinine levels, the potential causes, and the next steps if you get a low value on your creatinine test result.

Low Creatinine: What Levels Are Below Average?

Generally speaking, normal values of serum (blood) creatinine are 0.5 to 1.0 milligrams per deciliter (mg/dL) for females and 0.7 to 1.2 mg/dL for males. 

Scientists note that creatinine levels can vary widely depending on the method and timing of the test as well as a variety of individual factors, including:

• Your age
• Your diet (how much meat you eat)
• How much muscle you have (muscle mass)
• How physically active you are

Given the impact these factors can have on how much creatine you have in your blood, it’s important to talk with a healthcare provider about what level of creatinine is normal for you.

For example, a normal creatinine level doesn’t necessarily mean your kidneys are in perfect health, just as below- or above-average levels don’t necessarily mean there’s something wrong with your kidneys. 

Determining what “too low” means for you when interpreting creatinine test results will require the expertise of a healthcare provider who can take a holistic view of your individual factors as well as any health-related factors that might be causing your low creatinine levels.

Causes of Low Creatinine Levels

Low creatinine levels aren’t common, though that doesn’t automatically mean there’s a rare or serious kidney problem. Non-kidney-related factors usually cause low creatinine levels. 

Kidney-Related

High creatinine levels, rather than low creatinine levels, may indicate kidney injury or chronic kidney disease. This is because injury to the kidneys or kidney disease can make it harder for the kidneys to remove creatinine from the blood, meaning more stays in the blood, which may show up as higher than average values on a creatinine test.

Low creatinine values usually mean factors not related to the kidneys are at play.

Non Kidney-Related

Oftentimes, low creatinine levels signify health status or conditions that are not related to your kidneys. Common non-kidney-related causes of low creatinine include:

• Insufficient protein in your diet, which may come from following a vegetarian or vegan diet
• Muscle loss, such as from a chronic illness, nerve disorder, muscle-wasting disease, or aging, all of which can lead to your muscles decreasing in size
• History of amputation
• Malnutrition
• Pregnancy
• Serious liver disease

Since individual traits, personal lifestyle choices, and health issues can lead to low creatinine levels, it’s not easy to pinpoint what is causing low creatinine test results. Always ask a healthcare provider what your test results mean and which health factors may contribute to low creatinine levels.

How Do You Know If Your Creatinine Levels Are Low?

A blood test is needed to determine your blood creatinine level. Creatinine is measured as part of the basic metabolic panel (chem 7) and comprehensive metabolic panel tests. These tests may be ordered as part of routine bloodwork in a health check-up, before surgery, or when you need diagnostic testing for a health complaint.

When interpreting creatinine test results and comparing them against what is "normal" or "average," remember that a variety of personal, lifestyle, and health factors may be impacting your creatinine levels.

You may suspect specific causes based on your lifestyle choices or health history, but knowing when creatinine levels are too low or require medical attention needs a healthcare provider's expertise and medical advice.

Symptoms Associated With Low Creatinine Levels

Symptoms of low creatinine levels will depend on the underlying cause. For example, if insufficient protein leads to low creatinine levels, you might experience muscle weakness, brittle hair and nails, and be more prone to stress fractures.

If liver disease is the cause, you might experience symptoms of liver disease (such as yellowing of the skin and eyes), though not all symptoms are noticeable. 

Since symptoms of low creatinine vary by cause, it’s best to talk with a healthcare provider about what symptoms accompanying a low creatinine test result mean for you.

What Happens Next: Raising Low Creatinine Levels

Low creatinine levels do not always mean an intervention to raise creatinine is needed. It will depend on what creatinine levels are normal for you, given your individual and health-related factors.

If a healthcare provider determines that raising low creatinine levels is your next step, how to go about that will depend on the underlying cause of low creatinine levels and whether the low levels have a negative health effect. 

For example, as creatine is not found in plant-based proteins, researchers have shown that creatine supplementation may benefit vegetarian and vegan athletes in terms of athletic performance. More creatine intake will lead to more creatinine in the blood as the creatine gets metabolized.

Ultimately, if and when creatinine levels need to be raised should only be determined by a healthcare provider.

Summary

Low creatinine levels on a creatinine test indicate low levels of creatinine circulating in the blood. Compared to high creatinine levels, which may be a sign of kidney issues with filtering the blood, low creatinine levels are often not associated with kidney health but rather unrelated factors like dietary choices, muscle mass, pregnancy, and liver health.

When interpreting creatinine test results, it’s important to talk to a healthcare provider about what levels are normal for you, as they can vary from person to person.