Creatinineis a natural waste product that accumulates in the bloodstream after a person uses their muscles.
Healthykidneys(bean-shaped organs) filter creatinine out of the bloodstream, removing it from the body in urine.
Creatinine levels provide beneficial clues about kidney function and can be measured in the blood or urine.
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A high blood creatinine level and low urine creatinine level is often a sign of kidney injury or disease.
Possible symptoms of high creatinine in the bloodstream are also discussed.
Creatinine: What Levels Are Above Average?
Lastly, the reference range for creatinine values may vary slightly among laboratories.
Always speak with a healthcare provider about individual test results.
High Blood Creatinine
A high blood creatinine level may indicate kidney injury or disease.
The eGFR is a formula that approximates the filtering abilities of the kidneys.
In addition to a creatinine level, it incorporates a person’s age and sex.
In healthy adults, a normal eGFR is usually more than 90.
Average Urine Creatinine
A urine creatinine test measures the level of creatinine in the urine.
Low Urine Creatinine
A low level of creatinine in the urine may indicate kidney injury or disease.
To evaluate kidney function, urine creatinine may also be measured as part of a urine albumin-creatinine ratio.
The urine albumin-creatinine ratio compares thealbuminlevel with the creatinine level in a urine sample.
Kidney-Related Causes
Most people have two kidneys.
They are on either side of the spine, just above the waist and below the rib cage.
Left untreated, the kidneys may nearly stop working altogether.
At this pointcalledend-stage renal disease (ESRD)dialysisor akidney transplantis required to live.
The most common causes of CKD arediabetesandhypertension(high blood pressure).
How Do You Know If Your Creatinine Levels Are High?
Symptoms Associated With High Blood Creatinine Levels
Many people with high blood creatinine levels have no symptoms.
For acute kidney failure, this may be hours to days, depending on the underlying cause.
This may mean seeing anephrologist(a doctor specializing in kidney health) if kidney disease is suspected.
Thetreatment of kidney diseasehas several goals.
Summary
Creatinine is produced during regular muscle use.
It is a marker of kidney function because the kidneys remove it from the body through urine.
A high blood creatinine level often indicates an acute or chronic kidney problem.
Numerous factors, including age, sex, body size, diet, and activity, influence creatinine levels.
Lowering elevated blood creatinine levels involves treating the underlying causefor example, managing kidney disease.
It’s essential to discuss next steps with a healthcare provider if you have a high creatinine level.
2021;9:793446. doi:10.3389/fped.2021.793446
Asif AA, Hussain H, Chatterjee T.Extraordinary creatinine level: a case report.Cureus.
2020;12(7):e9076.
doi:10.7759/cureus.9076
Weinstein JR, Anderson S.The aging kidney: physiological changes.Adv Chronic Kidney Dis.
2015;16:21. doi:10.1186/s12882-015-0012-x
University of Rochester Medical Center.Creatinine (blood).
National Kidney Foundation.Kidney tests.
The Renal Association.About eGFR.
National Kidney Foundation.Estimated glomerular filtration rate (eGFR).
St Louis, MO: Elsevier; 2023:chap 34.
Brigham Young University.Kidney function tests.
Webster AC, Nagler EV, Morton RL, Masson P.Chronic kidney disease.Lancet.
2019;322(13):1294-1304. doi:10.1001/jama.2019.14745
