A creatinine blood sample would most likely be performed as part of your yearly check-up. In some cases, your doctor may also request a urine creatinine clearance test. High blood creatinine levels can indicate that your body’s ability to eliminate waste products-an important kidney function-is impaired.
Even if you are feeling fine right now, an elevated blood creatinine level may be cause for concern. In addition, if you’ve been infected with COVID-19, your creatinine levels should be checked on a regular basis.
Medical experts discuss the causes and symptoms of elevated creatinine levels, when to be concerned, and how to take action now to avoid future kidney problems. Kidney Performance Your kidneys are two bean-shaped organs located on each side of your spine, just beneath your ribcage. Kidneys are part of the urinary tract and serve several functions throughout the body:
- Filtering the blood with urine to remove waste and excess fluid.
- Keeping water, Nutrients like vitamin D, and Minerals like calcium, Phosphorus, sodium, and Potassium in balance.
- Making hormones that calm blood pressure, produce red blood cells, and keep bones strong.
- Blood flows nonstop into the kidney via the Nephrons. Each kidney has one million nephrons. A glomerulus, which filters the blood, and a tubule, which returns vital minerals and Nutrients to the blood while removing excess fluid and waste products, make up these tiny units.
Creatinine Suggestions
“Creatinine is essentially a byproduct of Skeletal muscle break down.” accordingly to Dr. Amy Yau of the Ohio State University Wexner Medical Center. “It can come from a variety of sources, including the body’s own production, the diet, and cell break down.”
Creatinine levels are one way to assess how well the kidneys work. “We use creatinine to estimate kidney function because creatinine is ‘freely filtered,'” explains Yau. “Because it’s freely filtered by the kidney, we know what a normal creatinine level should be in most people with normal kidney function.”
Creatinine levels, however, do not tell the entire story. They are used in conjunction with a variety of other laboratory results, such as:
- The rate of glomerular filtration. The glomerular filtration rate (GFR) is an estimate of how much blood passes through the glomeruli each minute. “Typically, we take creatinine and plug it into an equation,” Yau explains. “There are numerous equations for guessing GFR, which is what really tells us how well the kidney filters.” The GFR equation is stratified according to your age. So, what might be a normal creatinine in a 20 year old may be different or a not so worrying creatinine in an 80 year old.”
- Nitrogen in the blood. BUN measures the amount of urea nitrogen in the blood, which is a waste product of protein digestion. Healthy kidneys get rid of protein waste. According to Yau, BUN is an indirect marker of kidney function, but it can also be affected by other factors such as dehydration, certain medications, and a high-protein diet. As a result, doctors combine the creatinine, GFR, and BUN results to get an idea of how the kidney is doing.
Creatinine Test Results
Creatinine levels in the blood are measured in mg/dL. Normal blood creatinine levels, which fall within a range, differ from person to person. “Normal creatinine levels are typically between 0.7 and 1.1 or 1.2,” says Dr. Ziyad Al-Aly, a clinical epidemiologist at Washington University School of Medicine in St. Louis.
“When creatinine levels are high, it actually indicates that the kidney is not functioning properly,” Al-Aly explains. “It doesn’t get rid of all the toxins in the body.” When creatinine levels are low or normal, you can assume that the kidney is filtering the blood and working properly.”
Certain factors influence a patients normal creatinine levels. Because creatinine is produced by Skeletal muscle cells, your baseline creatinine level is affected by your weight and muscle mass. Bodybuilders’ creatinine levels may be higher, whereas women’s creatinine levels are slightly lower than men’s. Amputations would also affect baseline creatinine, according to Yau. “In general, I tell my patients that a creatinine level of about 1.0 is considered normal,” she explains. Another factor to consider is stability, or how quickly creatinine levels change, according to Al-Aly. “So, even if that creatinine is 1.0 or close to 1.0, if it was 0.5 two months ago and now it’s 1.0, that’s a pretty significant change,” he says. If, on the other hand, the creatinine level has been stable at 1.0 for months or years, he says, “that makes me feel a little bit more reassured.”
Experts Advice
“There is no ‘panic number,’ per se,” Al-Aly says of abnormally high creatinine levels. Instead, he explains, “we look at things dynamically.” “So if there’s a jump, like someones normal creatinine is 1.0 and then it suddenly jumps to 5.0, I’d be concerned.” What matters is the magnitude of the change.
Al-Aly points out the importance of patients not thinking Creatinine and glomerular filtration rate trends are the same. GFR works in the opposite direction, he claims, and a good number can reach 100%. When GFR is high, it indicates that the kidneys are working properly – everything is fine. Lower GFR indicates impaired kidney function and is an statement of disease.
Creatinine Clearance in Urine
If your creatinine blood test result is high, your doctor may want to know more. You will be given a handheld urinal (for men) or a urine collection ‘hat’ (for women) and an opaque plastic jug, as well as a homework assignment to collect your urine for the next 24 hours in order to provide a follow up sample for further testing.
You’ll also be asked to drink at least eight glasses of fluid during that time period in order to provide an adequate sample for measuring creatinine clearance, or how quickly your kidneys remove creatinine from your body.
As part of their inpatient care, patients may be subjected to a 24-hour urine collection. Significantly elevated creatinine levels or upward trends would necessitate a thorough diagnostic work.
Although many people have no early signs of kidney disease, others may experience the following:
- Edema (swelling) in the lower legs or around the eyes.
Vomiting or nausea - Shortness of breath caused by fluid in the lungs.
- Sleep issues.
- Unknown cause of weight loss.
- Weakness or exhaustion
- Itchy, dry skin.
- Concentration is difficult.
- Peeing more or less frequently than usual.
Once the underlying cause of decreased kidney function is identified, your health care team can devise a treatment plan to improve kidney function, such as starting blood pressure or diabetes medication. If chronic kidney disease is the problem, you will almost certainly need to see a kidney specialist, or nephrologist, for disease-specific treatment.
Keep in mind that creatinine levels alone are insufficient for determining.
