The kidney function tests are a group of tests performed to assess how well your kidneys are working. They measure levels of various substances, including several minerals, electrolytes, proteins, and glucose in the blood. They can be used as part of general health screening, for someone who is at risk of developing kidney disease, or to monitor someone who has been diagnosed with reduced kidney function or kidney disease.
What is being tested?
A kidney function panel is a group of tests that may be performed together to evaluate kidney (renal) function. The tests measure levels of various substances, including several minerals, electrolytes, proteins, and glucose (sugar), in the blood to determine the current health of your kidneys.
The kidneys are a pair of bean-shaped organs located at the bottom of the ribcage to the right and left of the spine. They are part of the urinary tract and perform a few essential roles and functions within the body.
If the kidneys are not functioning properly, waste products can accumulate in the blood and fluid levels can increase to dangerous volumes, causing damage to the body or a potentially life-threatening situation. Numerous conditions and diseases can result in damage to the kidneys. The most common causes of and main risk factors for kidney disease are diabetes and hypertension.
The individual tests included in a kidney function panel can vary by laboratory, but the tests typically performed include:
Electrolytes – electrically charged chemicals that are vital to normal body processes, such as nerve and muscle function; among other things, they help regulate the amount of fluid in the body and maintain the acid-base balance. Electrolytes include:
A calculated value may also be reported with a kidney function panel:
How is it used?
A kidney function panel may be used to evaluate kidney function, to help diagnose kidney-related disorders, to screen those who may be at risk of developing kidney disease or to monitor someone who has been diagnosed with kidney disease.
When is it requested?
A healthcare practitioner may order a kidney function panel when someone has signs and symptoms of kidney disease, though early kidney disease often does not cause any noticeable symptoms. It may be initially detected through routine blood or urine testing. Examples of some signs and symptoms include:
What does the result mean?
Kidney function panel test results are not diagnostic but rather indicate that there may be a problem with the kidneys and that further testing is required to make a diagnosis and determine the cause. Results of the panel are usually considered together, rather than separately. Individual test result can be abnormal due to causes other than kidney disease, but taken together with risks and/or signs and symptoms, they may give an indication of whether kidney disease is present.
The following table summarises what results might mean in relation to kidney.
|TEST||ASSOCIATION WITH KIDNEY DISEASE/ DYSFUNCTION|
|Concentrations of electrolytes in the blood can be affected by kidney disease in different ways depending on the cause, with some concentrations decreasing while others increase. In general, kidney dysfunction or disease can cause an imbalance among the electrolytes. When these positively and negatively charged ions are out of balance, it can affect the fluid balance and/or pH of the blood. As kidney dysfunction worsens, complications such as metabolic acidosis may result.|
|Phosphorous||High blood concentrations are associated with kidney disease.|
|Calcium||Low blood concentrations may be seen with kidney failure.|
|Albumin||A low blood concentrations may indicate that the kidneys cannot prevent albumin from leaking into the urine and being lost.|
|Urea||High results suggest impaired kidney function caused by acute or chronic kidney disease, damage, or failure, or due to another condition causing decreased blood flow to the kidneys, such as CHF or dehydration, or causing obstruction of urine flow, such as prostate disease or kidney stones.|
|Creatinine||High blood concentrations suggests impaired kidney function due to conditions listed above for urea.|
|Glucose||High blood concentrations indicates diabetes, a common cause of kidney disease.|
|Cystatin C||A high serum cystatin C result indicates a low GFR (glomerular filtration rate).|
|eGFR||Calculated from the blood creatinine test result; an eGFR below 60 mL/min suggests that some kidney damage has occurred; an eGFR below 15 indicates kidney failure.|
Is there anything else I should know?
Additional testing may be performed, such as kidney imaging or a kidney biopsy, if blood and urine testing indicate the possibility of kidney disease.
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