What is Creatinine in Blood Test? What is High and Low Creatinine Level? Causes & Treatment?
- Health Garden
- Apr 24, 2024
- 4 min read
Updated: Jun 16, 2024
Creatinine in a blood test is a test that measures the amount of creatine in your blood.
Creatinine is a chemical compound left over from energy-producing processes in your muscles. Healthy kidneys filter creatinine from the blood. Creatinine leaves your body as a waste product through urine. Therefore, the creatinine test is a measure of how well the kidneys filter waste from the blood. In other words, it shows whether the kidney is working well or not.
Creatinine can be measured with both a blood test and a urine test.
Your doctor may ask you to fast for 12 hours before the test or to avoid protein consumption.
What is A Normal Creatinine Level in Blood Test ?
The blood creatinine test measures the amount of creatinine in the blood and gives general information about kidney functions. However, people's muscle mass, age, activity level and nutrition are not the same. These factors may cause misinterpretation of results. Therefore, blood creatinine level is evaluated together with variables such as age, weight, height and gender. This calculation, called the estimated glomerular filtration rate (eGFR), measures how fast the kidneys filter blood. eGFR gives better results regarding kidney function and can help show how serious kidney damage may be.
By comparing creatinine levels in blood and urine, one can estimate how quickly the kidneys filter creatinine, such as eGFR. This is called creatinine clearance calculation.
Blood creatinine levels can be compared to the BUN (blood urea nitrogen) level. This can help find the cause of the kidney problem.
A normal creatinine value in a blood test is between 0.7 - 1.3 mg/dL for adult men and 0.6 - 1 mg/dL for adult women. Reference values may vary slightly between laboratories.
An eGFR score below 60 indicates kidney disease. The range of scores below 60 can be used to monitor treatment and disease progression.
What is High Creatinine Level in Blood Test?
High creatinine in a blood test means a creatinine value above 1.3 mg/dL for men and 1 mg/dL for women. Reference values may vary slightly between laboratories.
What Causes High Creatinine Level in Blood Test?
High creatinine may be a sign of:
Infection
Poor blood flow to the kidneys
Kidney disease or injury, including a blockage in the urinary system or kidney failure
A condition that affects your kidneys, such as heart failure or diabetes
Dehydration
Muscle disorders and injuries
Muscular dystrophy
Intense exercise
A diet rich in meat
Drug Toxicity
Some health problems during pregnancy can also cause an increase in creatinine.
High Creatinine Symptoms
Nausea and vomiting may occur with high creatinine levels. Possible symptoms that may be seen in addition to these are:
Swelling in the hands and feet or swelling of the eyelids
Dry skin, itching or numbness
Exhaustion
Frequent urination, pain and blood in urine,
Loss of appetite and weight loss
Muscle cramps
Nausea and vomiting
Shortness of breath
Sleep problems
Edema formation in the body
Chest pain
How to Treat High Creatinine Level?
Treatment of high creatinine depends on the underlying cause. Additional tests may be requested for this. After a definitive diagnosis is made, your doctor will apply the appropriate treatment protocol. If there are problems with eating habits and exercise, lifestyle changes may help normalize high creatinine levels. An increase due to medication use may require rearranging the dose or changing the medication.
What is Low Creatinine Level in Blood Test?
Low creatinine in a blood test means a creatinine value below 0.7 mg/dL for men and 0.6 mg/dL for women. Reference values may vary slightly between laboratories. Low creatinine levels are not very common.
What Causes Low Creatinine Level in Blood Test?
Low Muscle Mass: Since muscle density directly affects the creatinine value, low muscle mass causes creatinine values to decrease. Muscle mass can decrease due to aging, malnutrition, and serious muscle diseases such as myasthenia gravis and muscular dystrophy.
Excessive Weight Loss: Severe weight loss also causes a decrease in muscle mass. As a result, low creatinine is inevitable.
Liver Diseases: Poor liver function affects creatinine production.
Excessive Water Loss: Pregnancy, excessive water intake or some medications cause water loss in the body. In this case, the creatinine value may decrease.
Pregnancy: When you are pregnant, blood flow to the kidneys increases. This increases the excretion of creatine from the body. For this reason, the creatinine level in the blood remains lower during pregnancy.
Low Creatinine Symptoms
Symptoms of low creatinine depend on the cause.
Symptoms of falling creatinine due to low muscle mass include muscle pain, muscle stiffness, muscle weakness and decreased movement.
In cases of low creatinine due to the liver, abdominal pain, jaundice, abdominal swelling, pallor, tar-colored or bloody stools may occur.
How to Treat Low Creatinine Level?
To treat low creatinine, it is necessary to know the underlying factors.
If the underlying cause is a muscle disease, treatment aims to reduce muscle pain, weakness and degeneration.
If creatinine levels are low due to decreased muscle mass, drug treatment may not be necessary. In this case, changes in lifestyle and nutrition are required to increase muscle mass. Increasing the difficulty level of the exercises and exercising regularly increases muscle mass. If low muscle mass is caused by improper nutrition or excessive weight loss, it is recommended to consume foods containing plenty of protein frequently.
If the underlying cause of low creatinine is liver functions, it is recommended to make changes in nutrition as well as medication. These changes include proper nutrition and limiting or even stopping alcohol consumption if possible.