Kidneys play a vital role in filtering the waste products in the body. It maintains fluid balance in the body by producing necessary hormones. Regular kidney function tests are essential for assessing the health and functionality of this vital organ. This blog is a guide to the various tests conducted to check the functions of the kidney, their significance and what can be expected during the test.

Importance of Healthy Kidney Functioning

Kidneys, an essential organ in our body, help maintain overall health. Some of the important functions of kidneys include:

• Kidneys are the filters of the body which continuously filter the waste products from the blood.
• Kidneys also control the blood pressure level in the body by controlling the level of fluids. They produce a hormone called renin that helps constrict blood vessels and regulate blood volume, thereby influencing blood pressure levels.
• Kidneys produce a hormone, called erythropoietin, which helps in the formation of red blood cells in the bone marrow. Red blood cells are necessary for the production of oxygen in the body.

Hence, maintaining healthy kidney function is vital for preventing kidney diseases and ensuring the proper functioning of several body functions.

Tests to Check Kidney Function

It is essential to know what tests are done to check kidney function. The following tests are usually included to determine kidney health:

1. Urine Tests

• Urinalysis: This test examines urine for the presence of protein, blood cells, glucose, and other substances, providing valuable insights into kidney function and potential underlying issues.
• Urine Protein Test: By measuring the amount of protein in the urine, this test helps identify potential kidney damage or dysfunction, as excessive protein in urine can indicate impaired kidney filtration.

2. Blood Test

• Serum Creatinine Test: Creatinine is the waste product of the muscles, which is usually cleared out by the kidneys. KFT is done to evaluate the creatinine level in the body. Increased creatinine levels may cause the kidneys to malfunction and hamper it’s ability to filter out blood.
• Blood Urea Nitrogen (BUN) Test: This test checks the urea levels in the blood and examines how well the kidney filters the blood and performs its function. Abnormal BUN levels can suggest kidney dysfunction or poor filtration and elimination of urea nitrogen.
• Glomerular Filtration Rate (GFR): GFR calculates the rate at which waste products are filtered from the blood. It provides an overall measure of kidney function and helps assess the severity of kidney disease. A lower GFR indicates reduced kidney function and poor filtration.

3. Imaging Tests

• Kidney Imaging: Techniques like ultrasound, CT scan, or MRI are employed in kidney imaging to obtain detailed images of the kidneys. This is helpful in the identification of other problems, like tumours, cysts etc., that hampers the overall functioning of the kidney.
• Kidney Biopsy: The extraction of small samples of kidney tissue is known as kidney biopsy. It is performed to diagnose certain kidney conditions, assess the severity of kidney damage, and determine the appropriate treatment plan. A kidney biopsy provides valuable insights into the underlying cause of kidney dysfunction or the presence of specific kidney diseases.

When to Get a Kidney Function Test?

Kidney function test (KFT) helps monitor kidney disease progression, evaluate treatment effectiveness, and make necessary adjustments to the management plan.

A kidney function test is necessary:

• Before carrying out certain medical procedures such as a contrast CT scan.
• Before starting medications that can impact kidney function.
• To screen the kidneys for any issues in people with hereditary issues, blood pressure, or diabetes.
• To monitor hormonal changes and increased blood volume during pregnancy.
• To assess the kidney function if the person experiences specific symptoms like changes in urination patterns, blood in urine, or swelling in the extremities

What to Expect After a Kidney Function Test?

After a kidney function test, the results will be analyzed by a nephrologist (kidney disease specialist). Depending on the findings, further evaluations or treatments may be recommended. In case of an abnormality, the doctor may recommend lifestyle modifications, medication adjustments, or dietary changes. Regular monitoring of kidney function may also be advised to track progress and ensure optimal kidney health.

Conclusion

Understanding kidney function tests is vital for assessing kidney health. Tests like GFR, BUN, and creatinine provide valuable information about kidney function and aid in diagnosing kidney conditions. Regular monitoring, especially for high-risk individuals, allows early detection and prompt medical intervention.

Book A Kidney Function Test

FAQs

Q. How often should kidney function tests be done?

The kidney function tests should be conducted depending on age, other medical factors and health history. Usually, a kidney function test must be perform annually after the age of 30.

Q. Can kidney function tests detect all types of kidney diseases?

Kidney function tests can detect various kidney diseases, however, some severe conditions such as kidney failure may require additional tests or procedures for a definitive diagnosis.

Q. Do kidney function tests require any special preparation?

Generally, for determining the levels of serum creatinine and blood urea nitrogen, no special preparation is required, and can be carried out at any time of the day.

Medically reviewed by Dr Dhanunjay Reddy.