Kidney Function Test and Its Types

The kidneys play a vital role in maintaining our health by filtering the waste materials from the blood and excrete them from the body through urine. There are a host of kidney function tests available such as Urinalysis, Serum creatinine test, BUN test, etc.

Kidneys are responsible for performing a plethora of functions such as filtering the wastes, controlling the level of water and other essential minerals in the body. Some of the other functions of kidneys are, they help in the production of hormones that regulate blood pressure, vitamin D, Red Blood Cells. If your kidneys are facing problems in performing these functions, you need to get a kidney function test done as early as possible.

Symptoms of Kidney Problems

The symptoms of kidney problems are:

• High blood pressure
• Blood in the urine
• Frequent urge to urinate
• Difficulty in urinating
• Swelling of the hands and feet due to the build-up of fluids in the body.

If these symptoms are occurring simultaneously, it suggests that the kidneys aren’t working properly. Therefore a proper kidney function blood test should be done to determine the possible reasons.

Types of Kidney Tests

For a proper test of the kidneys, doctors order a set of tests that helps in estimating the Glomerular Filtration Rate (GFR).GRF tells the doctors about how quickly the kidneys are clearing waste from the body.

Following are some of the important blood test for kidney function:

Urinalysis

Urinalysis screens the presence of protein and blood in the urine. Several factors can lead to increase in the level of protein but not all of them are related to the disease. The presence of infection in the urine can increase the level of protein but so does a heavy physical workout. Therefore, doctors need to repeat this test after few weeks to see if the result are similar.

Doctors also order the patient to provide a 24- hour urine collection sample that helps them to witness how fast the waste product called Creatinine is clearing from the body.

Serum Creatinine Test

Creatinine is the breakdown product of muscle tissue. Serum Creatinine blood test examines the building up of creatinine in the blood. Healthy kidneys completely filter creatinine from the blood. According to National Kidney Foundation, the level of creatinine is higher in men (1.4) than women (1.2).

Blood Urea Nitrogen (BUN)

Blood Urea Nitrogen test examines the presence of waste products in the blood. It measures the amount of nitrogen in the blood. However, not all BUN tests are done due to kidney damage.

Some of the common medications that help in increasing the BUN are doses of aspirin and antibiotics. A normal range should be between 7 to 20.A higher value can also suggest several other health problems.

Estimated Glomerular Filtration Rate (GFR)

This test helps in examining the rate of waste filtration by the kidneys. Following are several factors that determine the rate are:

• Test results, especially creatinine level
• Age
• Gender
• Height and weight of the patient.

Any kidney function test result lower than the value 60 may be a warning sign of kidney disease.

How the tests are obtained?

For having a proper kidney function test, doctors usually require 24- hour urine and a blood test sample.

• 24- Hour urine sample is basically a creatinine clearance test that provides the doctor an idea of how much creatinine the body expels in a single day.
• Blood samples usually involve BUN and Serum Creatinine Tests that require blood samples taken in a laboratory.

The author is an avid health blogger who writes about health related issues, diseases, Tests and Treatments.