Blood Test and Urine Tests for Evaluating Kidney Function
Kidney function test is used to find how well your kidneys are and which CKD stages your medical condition is. Blood tests and urine tests are the common lab values for kidney functions.
Blood Test for Kidney Function
Creatinine Test. Creatinine is a by-products of muscle energy metabolism, which should be filtered out of the body by kidneys in normal conditions. The creatinine levels are affected by many factors and the most important two causes are muscle mass and kidney functions. If your doctor cannot find objective causes for your increased creatinine level, usually kidney function decline will be the possible answer. BUN (blood urea nitrogen) Test. Urea is a waste products of protein metabolism, which is formed in the liver. This waste product is filtered from the blood and excreted in the urine by the kidneys. This test measures the amount of nitrogen contained in the urea. Urine test is suggested to be taken along with blood creatinine test. Thus, your doctor will make a more specific indicator of kidney function.
Other Blood Test. Other blood tests include many lab values, including glucose, sodium, uric acid, potassium, protein, chloride, phosphorus, bicarbonate, magnesium.
Urine Test for Kidney Function
Urine protein test. Healthy kidneys filter all proteins from the bloodstream and then reabsorb them, allowing no protein, or only slight amounts of protein, into the urine. The persistent presence of significant amounts of protein in the urine, then, is an important indicator of kidney disease.
Urea clearance test. The urea clearance test requires a blood sample to measure the amount of urea in the bloodstream and two urine specimens, collected one hour apart, to determine the amount of urea that is filtered, or cleared, by the kidneys into the urine.
Creatinine clearance test. This test evaluates how efficiently the kidneys clear a substance called creatinine from the blood. Creatinine, a waste product of muscle energy metabolism, is produced at a constant rate that is proportional to the individual's muscle mass. Determination of the blood creatinine level is also required to calculate the urine clearance.
Urine osmolality test. Urine osmolality is a measurement of the number of dissolved particles in urine. It is a more precise measurement than specific gravity for evaluating the ability of the kidneys to concentrate or dilute the urine. The test may be done on a urine sample collected first thing in the morning, on multiple timed samples, or on a cumulative sample collected over a 24-hour period.
Both blood test and urine test only make a first diagnosis of kidney disease. For final and detailed kidney function, you need more specific diagnosis based on your own condition. You can leave your symptoms and other indications related to your kidneys below, and our experts will help find the tests for you.
Tag: CKD Diagnosis
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