Renal function tests analyze blood samples to detect any kidney related problems. Renal function tests are a set of tests performed in blood to assess the kidney damage or kidney failure.
Creatinine test is used to measure the levels of creatinine in your blood. Creatinine is a waste product from the breakdown of creatine found in your muscle. This test is performed to see how well your kidneys are working.
Glomerular filtration rate (GFR) test is used to check the functioning of your kidneys. Glomerular filtration rate is the speed at which blood is filtered per minute.
This test measures the amount of urea nitrogen in the blood. Urea is a waste product formed in the liver as a result of protein breakdown. This urea is then released into the blood by the liver. Normally, it is then removed from the blood by the kidneys. Kidneys filter urea and it gets removed from the body through urination.
Kidneys are the main filtration system of the body. They efficiently filter blood and remove waste products from it and excrete them through urine and prevents the loss of proteins and blood cells. Each kidney consists of several glomeruli. Glomeruli are the tiny filters present inside the kidney. If there is an impairment in kidney functioning it means the glomeruli has failed to filter efficiently. In glomerular filtration rate, the amount of blood passing through the glomeruli per minute is estimated thus calculating the functioning of kidneys.
This test may be recommended to you if you have diabetes, high blood pressure, heart disease, kidney stones, frequent urinary tract infections, kidney failure, polycystic kidney disease or if you experience certain symptoms like difficulty in urinating, foamy urine, blood in urine, mid-back pain, unexplained swelling of the body, puffiness around your eyes, etc. This test may also be recommended if you take any medicines that might affect the kidney function or if you have a family history of kidney diseases.
Some medications may interfere with the test results like cimetidine, cisplatin, ibuprofen, trimethoprim, flucytosine, cephalosporin antibiotics like cephalexin, cefixime, ceftriaxone, etc, aminoglycosides like streptomycin, amikacin, gentamicin, neomycin, etc. Certain conditions also affect the test results such as below 18 years, severely malnourished, underweight or overweight, bodybuilder, eating a lot of meat, eating low-meat diet or a vegetarian diet, change in kidney functions, pregnancy, neuromuscular disorder, a muscle-wasting disease. Hence inform your doctor or technician about all your current medications and medical conditions prior to the test.
Inform your doctor if you are on any medications, have any allergies or underlying medical conditions before your RFT. Your doctor will give specific instructions depending on your condition on how to prepare for RFT.
No specific preparation is required for this test.
Factors like age, gender, race, health history and glomerular filtration rate (GFR) are also considered in measuring the functioning of the kidney.
Creatinine level depends on the muscle mass you have. It varies in men, women, and children depending on their age. Your test results may not always indicate a problem with your kidney. Ask your healthcare provider about your results.
If the creatinine levels are more than the normal level then it may indicate kidney disease, obstruction in your urinary system, congestive heart failure, dehydration, diabetes, shock, overactive thyroid gland, problems during pregnancy like such as seizures due to eclampsia or high blood pressure caused by preeclampsia etc.
If the creatinine levels are less than the normal level then it may be due to severe liver disease, muscle loss, not enough protein in your diet, etc.
If glomerular filtration rate test results are slightly less than the normal range it may indicate no damage to the kidney, lower than normal range may indicate mild damage to kidney, if the results are very less than the normal range it may indicate severe loss of kidney function and if the results are extremely lower than the normal range then it may indicate kidney failure.
High levels of urea nitrogen indicate that your kidneys are not working properly. Low levels of urea nitrogen are not very common. This can be due to liver disease or damage, malnutrition, overhydration or lack of protein in the diet.
If you get abnormal test results, consult your doctor immediately. Your doctor may recommend other tests depending on your results.
|MALE||All age groups||0.7 to 1.3 mg/dl|
|FEMALE||All age groups||0.6 - 1.1 mg/dl|
|UNISEX||All age groups||The observations vary depending on the cause|
|UNISEX||All age groups||> 90ml/min/1.73 metre square|
|UNISEX||< 18 years||7 - 20 mg/dl|
|UNISEX||> 18 years||5 - 18 mg/dl|