Which blood test is used to assess kidney function?

The blood urea nitrogen (BUN) test is specifically designed to evaluate kidney function. This test measures the amount of nitrogen in the blood that comes from urea, a waste product formed from the breakdown of proteins. Healthy kidneys filter urea from the blood and excrete it in urine. When kidney function is impaired, the BUN level can rise, indicating that the kidneys are not filtering waste effectively. Therefore, a BUN test is a critical tool in assessing how well the kidneys are working and can help identify kidney disease or dysfunction.

The other tests mentioned serve different purposes and do not provide a direct assessment of kidney function. The complete blood count (CBC) primarily provides information about the body's overall health and can highlight issues such as anemia or infection. The blood glucose test is used to monitor and diagnose conditions related to blood sugar levels, such as diabetes. The liver function test (LFT) evaluates the health of the liver by measuring various enzymes and substances in the blood, and it does not directly reflect kidney performance.