What lab test is typically used to evaluate renal function?

The serum creatinine level is a critical lab test used to evaluate renal function because creatinine is a waste product produced from muscle metabolism that is primarily eliminated from the body by the kidneys. An elevated serum creatinine level can indicate impaired kidney function, as the kidneys' ability to filter and excrete creatinine decreases when they are not functioning properly. This makes the test particularly valuable in assessing renal health and monitoring renal diseases.

While urea nitrogen levels can also provide insight into kidney function, they can be influenced by factors such as hydration status and protein intake, making them less specific than serum creatinine. An electrolyte panel assesses the levels of various electrolytes in the blood, which can indicate issues related to kidney function but does not directly measure how well the kidneys are filtering waste. A complete blood count is useful for evaluating overall health and detecting a variety of conditions but does not specifically assess renal function. Thus, the serum creatinine level is the most direct and widely used test for evaluating renal function in clinical practice.