The functions of normal kidneys are to remove the metabolic waste which is in the bloodstream, regulate the balance of water in the body and to maintain both alkalinity and acidity in the body fluids. If there is any symptom which is bothering you a urine and blood test will confirm whether the kidneys are functioning normally. Most often the kidney function test results are looked at along with the liver function test results to see where the basic problem lies. People who have diabetes or have been on drugs for treating arthritis or pain management would need to undergo both kidney function blood test as well as liver function test to determine the extent of damage and the cause of the problem.
Several tests are conducted to assess whether the kidney functions are within the normal parameters. Serum creatinine is one of the tests done to evaluate these functions. Creatinine is a metabolic waste product which is filtered by the kidneys from the blood and excreted in the urine. The level of blood creatinine is maintained by excretion but if the kidney function is not normal then the levels will be elevated. Age and gender could also affect the levels of creatinine but this should be within the normal parameters. Kidney function blood test normal range for serum creatinine is 0.8 to 1.2 mg/dl in males and 0.6 to 0.9 mg/dl in females. Along with the blood test a creatinine clearance is done to see the level of creatinine in the urine. For this a 24 hour collection of urine is needed. The normal levels differ according to the age of the person and decreases after the person reaches forty years of age with every decade.
A urine analysis is conducted to screen kidney function problems. The indications which show any abnormality are bilirubin, ketones, protein and glucose in the urine. The alkalinity and acidity also gives an indication of kidney problems. For urea clearance two samples of urine are collected an hour apart and this test shows how much of urea is being filtered by the kidneys. The normal range for urea clearance is 64to 99 ml/min. The test for urine protein needs a twenty four hour collection of urine and the normal range is less than or 150 mg of protein in this 24 hour collection. If there are any abnormalities found in these tests the doctor may decide on further tests or prescribe treatment on the basis of the existing results.
Kidney function blood test gfr or glomerular filtration rate is an accurate measure for the function of the kidneys and can gauge the extent of damage to them. This can be calculated with the creatinine test, gender, race and the age of the person.
Kidney function blood test eGFR or Estimated Glomerular Filtration Rate does not need any separate blood test and can be determined with the sample given for the creatinine test. This is done to assess the damage to the kidneys.