Which laboratory test is primarily used to assess kidney function?

The serum creatinine test is a key marker used to assess kidney function. Creatinine is a waste product produced from muscle metabolism, and it is typically removed from the bloodstream by healthy kidneys. When kidney function declines, the level of creatinine in the blood increases. This makes serum creatinine a reliable indicator of how well the kidneys are filtering waste products from the blood.

Monitoring serum creatinine levels helps healthcare providers determine the glomerular filtration rate (GFR), which is a crucial measure of kidney function. Elevated serum creatinine can indicate conditions such as acute kidney injury or chronic kidney disease and allows for timely intervention.

In contrast, other tests listed serve different purposes: a complete blood count evaluates overall health and detects a variety of disorders such as anemia and infection, liver function tests assess the health of the liver, and an electrolyte panel determines the levels of crucial ions in the blood which can be indicative of numerous conditions but does not specifically assess kidney function directly.