What is Creatinine?
Creatinine is a chemical waste molecule that is generated by muscle metabolism. Creatinine is produced from creatine, a molecule of major importance for energy production in muscles. Approximately 2% of the body's creatine is converted to creatinine every day. Creatinine is transported through the bloodstream to the kidneys. The kidneys filter out most of the creatinine and flush it out through urine. Because the muscle mass in the body is relatively constant from day to day, the creatinine production normally remains essentially unchanged daily. Most men with normal kidney function have approximately 0.6 to 1.2 milligrams/deciliters (mg/dl) of creatinine. Most women with normal kidney function have between 0.5 to 1.1 mg/dl of creatinine. Women usually have lower creatinine levels than men because women, on an average, have less muscle than men. Other factors that may affect the level of creatinine in the blood include body size, activity level, and medications.
What are reasons for elevated blood creatinine?
Any condition that impairs the function of the kidneys is likely to raise the creatinine level in the blood. The most common causes of chronic kidney disease in adults are diabetes and hypertension. It is important to recognize whether the process leading to kidney dysfunction (kidney failure, azotemia) is longstanding or recent. Recent elevations may be more easily treated and reversed. Other causes of elevated blood creatinine levels are:
- Certain drugs (for example, cimetidine or bactrim) can sometimes cause abnormally elevated creatinine levels
- Serum creatinine can also transiently increase after ingestion of a large amount of dietary meat; thus, nutrition can sometimes play a role in creatinine measurement
- Kidney infections, rhabdomyolysis, and urinary tract obstruction may also elevate creatinine levels
What are symptoms of elevated creatinine?
Some people may have an incidental finding of elevated creatinine on routine blood work without having any symptoms of kidney disease. In others, depending on the cause of the problem, different symptoms of elevated creatinine (indicative of kidney failure) may be present including:
- Feeling dehydrated
- Swelling (edema)
- Shortness of breath
- Other nonspecific symptoms such as nausea, vomiting, neuropathy, and dry skin
Creatinine and chronic kidney disease
When there is kidney damage or kidney disease, and the kidneys are not able to filter waste efficiently, there will likely be a rise in creatinine levels in the blood. Dialysis is needed whenever kidney function is too low to maintain health. However, creatinine is just one of many factors considered when deciding whether to recommend dialysis treatment. Some people who have no symptoms of illness at all find out they have advance kidney disease when high creatinine levels are detected in routine blood tests. When signs of diminished kidney function do arise, they may include loss of appetite, vomiting, itching, weakness and flu-like symptoms. Swelling in the legs and shortness of breath may occur if water builds up in the body.
Why is it important to check creatinine levels?
The kidneys maintain the blood creatinine in a normal range. Creatinine has been found to be a reliable indicator of kidney function. Elevated creatinine level signifies impaired kidney function or kidney disease. As the kidneys become impaired for any reason, the creatinine level in the blood will rise due to poor clearance of creatinine by the kidneys. Abnormally high levels of creatinine thus warn of possible malfunction or failure of the kidneys. It is for this reason that standard blood tests routinely check the amount of creatinine in the blood.
Methods to test creatinine
Creatinine can be tested in both the blood and in the urine. These tests can help evaluate kidney function. Serum creatinine is a test that draws blood and sends it to a laboratory to be analyzed to find out how much creatinine is in the bloodstream. Knowing your serum creatinine allows your doctor to calculate your creatinine level along with your age, gender to determine your glomerular filtration rate (GFR). GFR is a measure of kidney function. If you know a serum creatinine level, you can determine the stage of CKD. A low GFR, just like an elevated serum creatinine, is not always evidence of kidney disease. Ask your doctor to help you interpret your results.
Creatinine clearance (Ccr or CrCl) measures how much creatinine is cleared out of the body, or how well kidneys filter waste. Creatinine clearance requires a combination of a urine test and blood test. Because the urine has to be collected over a period of 24 hours, the creatinine clearance is usually done after first evaluating the serum creatinine and calculating the GFR.
Are you at risk for kidney disease?
Kidney disease can be found through lab tests or by symptoms. High blood levels of creatinine and urea nitrogen (BUN) or high levels of protein in your urine suggest kidney disease. Diabetics should have a yearly urine test for microalbumin, small amounts of protein that don't show up on standard urine protein test.
Do you know the causes of kidney disease and if you’re at risk? Take a 3-minute Kidney Disease Risk Quiz to see if you’re at risk for renal disease.
If you have signs of kidney disease, you should ask for a referral to a nephrologist, a specialist in treating kidney disease. A nephrologist will perform an evaluation then suggest medications or lifestyle changes to help slow the progression of kidney disease. To contact a nephrologist at DaVita you may call us at 9740426060 or fill the form :