When the body uses the amino acid creatine for energy, creatinine is left behind as waste. The levels of creatinine in the bloodstream or urine can be checked if there is a concern that someone may have a disease of the liver or muscles.
More often, low creatinine levels are a sign of losing muscle mass as people age, or it is a temporary condition during pregnancy or periods of illness, or due to malnutrition.
Contents of this article:
- Creatine is an amino acid made naturally in the body, with a small amount coming from food.
- It is used for energy in the body, made in the liver and found in muscles.
- Lower creatinine levels in an older adult, or in someone who is slightly underweight, should not be a serious cause for concern.
What is creatinine?
Creatine powder is a popular dietary supplement that may increase body mass.
The amino acid called creatine has gained popularity as a dietary supplement due to evidence that it may increase body mass, improve short-term intense exercise performance, and aid in recovery.
When creatine breaks down as it is used for energy, creatinine is created as a waste product.
Creatinine levels vary from person to person depending on factors such as body size, age, or gender, so there is no standard or 'normal' level.
Low creatinine levels could indicate a problem with the muscles or liver but may be due to something less serious, such as reduced muscle mass in older adults, or pregnancy.
Testing and how creatinine affects the body
Creatinine is always present in the bloodstream, where it is removed by the kidneys and leaves the body in urine.
Although it is a waste product, research suggests that creatinine in the body may also play a part in fighting disease, as it has been shown to stop the growth of bacteria.
Creatinine clearance is a test used by doctors that shows how well the kidneys are removing creatinine from the bloodstream.
The test is done using a timed urine sample, which means that all the urine someone passes in a set time period, such as 24 hours, is collected and tested to show how much creatinine has been removed from the body by the kidneys.
This test is most often used to judge high, rather than low creatinine levels in the body and is likely to be used alongside other tests to look at overall kidney health.
Causes of low creatinine
Pregnancy may be a cause of low creatinine levels.
There are four key causes of low creatinine:
- low muscle mass
- liver problems
- pregnancy or illness
Low muscle mass
Levels of creatinine are often linked with muscle mass or the amount of muscle in the body, which can decrease with age or illness.
Low levels may indicate that muscles are less strong or are deteriorating, for example with a disease such as muscular dystrophy (MD).
Older adults often lose some muscle mass with age, and this is not usually a serious medical concern.
Creatine is made in the liver, and an unhealthy liver that is not working properly will not be able to make the normal amount of creatine.
For chronic liver disease, there can be a 50 percent reduction in the production of creatine. This means that there will be lower levels of creatinine in the blood, which can be checked with a simple blood test called a serum creatinine test.
Although creatine is made naturally in the body, a small amount comes from food, so low levels of creatinine could relate to diet.
Creatine is mostly found in meat, so those who follow a vegetarian or low-protein diet are likely to have lower levels than people who eat meat.
A prolonged period of not eating, or having an illness that prevents someone from eating, could be another cause of low levels of creatinine.
Pregnancy is often a cause of low creatinine levels, which should return to normal after a woman has given birth.
Symptoms of low creatinine
Symptoms of low creatinine will vary depending on the underlying condition but can include:
- Low muscle mass: Lack of strength, difficulty exercising, a thin or frail body.
- Liver disease: Inflamed liver, which may cause pain in the upper right-side of the abdomen, fatigue or nausea.
- Diet-related: Feeling faint or dizzy, losing weight.
In the majority of cases, symptoms are unlikely to point clearly to low creatinine levels and could indicate other health problems.
A medical professional will test creatinine levels as part of a diagnosis if other symptoms are present, and a test is needed.
Low and high creatinine levels?
Usually, low creatinine means that there is too little creatine being produced in the body. This state will relate to the liver, muscles, or diet.
High levels of creatinine usually mean that there is too much creatine in the body, or that creatinine is not being filtered and removed from the body properly.
Creatinine levels often rise during intense exercise, as more creatine is burned for energy, or because someone may eat a high-protein diet.
High levels could also indicate a problem with the kidneys, as these organs get rid of waste products from the body to keep the blood clean.
If low creatinine levels indicate liver disease, then treatment may include quitting alcohol.
Low creatinine levels may indicate various different conditions, so a doctor will use test results alongside other checks to work out what the underlying issue could be.
If low creatinine levels, alongside other symptoms, show that someone may have liver disease, treatment is likely to start with medication and lifestyle changes. These changes could include eating a more healthful diet and giving up alcohol.
If someone has a muscle disease, treatment may include physical therapy, medication, or surgery to support them to remain mobile.
How to increase creatinine levels
Gentle exercise to increase muscle mass, or increasing creatine intake in the diet may help, particularly for those on a vegetarian diet who may not be eating enough protein.
For people who do high-intensity exercise, creatine as a dietary supplement is generally considered safe.
However, the body produces creatine naturally, and most people who eat a balanced diet and are moderately active should not need to supplement their diet.
Low creatinine levels can indicate an underlying health problem, such as liver disease, but if this is the case, it will usually present alongside other symptoms. In these instances, the condition will be best tested by a doctor.
More often, low levels of creatinine are a normal part of aging or a temporary issue that can be resolved with changes to diet.