Creatinine is a waste product the body makes when it breaks down muscle tissue. It is filtered out by the kidneys and excreted through urine.
Doctors may test your creatinine levels for several reasons, including kidney disease, diabetes, and certain medications. Your healthcare provider might also ask you to take a creatinine clearance test, which involves a blood draw and 24-hour urine collection.
What is Creatinine?
Creatinine is a breakdown product of muscle and protein metabolism produced at a relatively constant rate. First, the kidneys filter this waste out of the blood, passing through the urine (pee).
A serum creatinine level can help assess how well your kidneys are working. Creatinine levels should be checked regularly, especially if you have a health condition that may impact your kidneys.
In healthy people, what is a good creatine level should be relatively stable. However, when your kidneys are not working correctly, they can’t eliminate this waste product.
As a result, blood creatinine can rise or fall dramatically over time. This is why regular blood tests assess it to determine how effectively your kidneys operate.
If your creatinine levels are high, this is generally a sign of an underlying health problem that you must address. Your doctor will discuss what the results of your test mean to you.
Your doctor might also use a creatinine test and other tests, such as a blood urea nitrogen (BUN) test, to evaluate your kidney function. Your healthcare provider might order these tests as part of a routine physical or to monitor your health for conditions such as chronic kidney disease or diabetes.
You will need to provide a blood sample at the clinic or take a 24-hour urine collection at home to have your creatinine tested. Your test results will be compared to average values, which vary depending on your age and body mass index (BMI).
Creatinine Levels
If you’ve been a powerlifter ever or swam a race, you know that your body burns through energy fast. That energy comes from the amino acid creatine. However, when your muscles use it for power, a waste product is created called creatinine.
The kidneys filter the creatinine out of your blood and then excrete it through your urine. When your kidneys work correctly, your creatinine levels should be between 0.7 and 1.3 milligrams per deciliter (mg/dL) for men and 0.6 to 1.1 mg/dL for women.
High creatinine levels can signify an underlying health condition or problem, such as a bacterial kidney infection or chronic kidney disease. These conditions may require treatment to address the underlying cause and restore normal creatinine levels.
Some ways to reduce your creatinine level are eating right, drinking plenty of water, and managing any chronic health issues or medications you take. Creatinine can also be reduced by taking a creatine supplement, which is usually safe for you to consult your doctor first.
Green tea is a popular diuretic, and drinking it 2 to 3 times a day can help improve the filtration ability of your kidneys and increase your urine output. In addition, dandelion root tea has been shown to lower blood creatinine levels.
Creatinine Clearance Test
A creatinine clearance test determines how effectively your kidneys eliminate creatinine from your blood and urine. The test can be used to aid in the diagnosis of kidney illnesses such as chronic kidney disease and acute renal failure.
The test can also be used to track the evolution of the renal disease and see how well it responds to therapy. It may also be used to help decide whether to start dialysis.
Creatinine clearance is expressed in milliliters per minute per body surface area (mL/min/BSA). The normal range for males aged 19 to 75 is 77 to 160 mL/min/BSA. Lower results for your age group may suggest poor kidney function or diseases that decrease blood flow to your kidneys.
Creatinine Test Results
Creatinine test results can give healthcare providers a strong idea of how well your kidneys work. This information can help them diagnose chronic kidney disease, track the progress of kidney damage, and monitor medications that can affect your kidneys.
Normal blood creatinine levels range from 0.7 to 1.3 milligrams per deciliter (mg/dL) for men and 0.6 to 1.1 mg/dL for women. Levels may vary based on age, race, and body size.
Typically, the test is done by your doctor or other healthcare provider using a vein on your arm. You may feel a prick or stinging sensation when the needle is inserted, but this goes away quickly.
The laboratory will collect serum and urine samples over 24 hours if the test is done in a laboratory. Then, they will use a mathematical formula to estimate your glomerular filtration rate (GFR).
GFR measures how well the kidneys filter fluid and waste products from your blood. A GFR of 60 or more is considered normal, while a GFR below 60 indicates kidney damage or failure.