Kidney Function Tests
Introduction
Kidney function tests are a collective group of individual examinations and tests that are performed together to ascertain the functional capacity of the kidneys. These tests provide information about the overall health of the kidneys, their effectiveness in filtering waste products from the blood, and the balance of electrolytes and fluids in the body.
Types of Kidney Function Tests
There are several types of kidney function tests, each designed to measure a specific aspect of kidney function.
Blood Urea Nitrogen (BUN)
The Blood Urea Nitrogen (BUN) test measures the amount of nitrogen in the blood that comes from the waste product urea. Urea is produced when the liver breaks down protein and is removed from the blood by the kidneys.
Serum Creatinine
The Serum Creatinine test measures the amount of creatinine in the blood. Creatinine is a waste product that is produced by the muscles and removed from the blood by the kidneys.
Estimated Glomerular Filtration Rate (eGFR)
The Estimated Glomerular Filtration Rate (eGFR) test estimates how much blood passes through the glomeruli each minute. Glomeruli are the tiny filters in the kidneys that filter waste from the blood.
Urine Tests
Urine tests such as the Urine Albumin test and the Urine Creatinine test measure the amount of certain substances in the urine. These tests can help determine how well the kidneys are removing waste from the body.
Understanding Kidney Function Test Results
The results of kidney function tests can be complex and are best interpreted by a healthcare professional. However, some general principles can help patients understand their test results.
Blood Urea Nitrogen (BUN)
A high BUN level can indicate that the kidneys are not functioning properly. However, a high BUN level can also be caused by a high-protein diet, dehydration, or certain medications.
Serum Creatinine
A high serum creatinine level can indicate that the kidneys are not functioning properly. However, a high serum creatinine level can also be caused by a high-meat diet, certain medications, or strenuous exercise.
Estimated Glomerular Filtration Rate (eGFR)
A low eGFR can indicate that the kidneys are not functioning properly. However, eGFR can also be affected by age, sex, body size, and ethnicity.
Urine Tests
High levels of certain substances in the urine can indicate that the kidneys are not functioning properly. However, these levels can also be affected by diet, hydration status, and certain medications.
Conclusion
Kidney function tests are an important tool for diagnosing and monitoring kidney disease. By measuring the levels of certain substances in the blood and urine, these tests can provide valuable information about the health and function of the kidneys.