Which laboratory test is primarily used to evaluate renal function in primary care?

Creatinine is a key laboratory test used to evaluate renal function because it is a waste product produced by muscle metabolism that is normally filtered out of the blood by the kidneys. Elevated levels of creatinine in the blood indicate impaired kidney function, as the kidneys are not adequately removing this waste product. This makes it a reliable and commonly used marker in primary care settings for assessing renal health.

The creatinine level can provide insights into the glomerular filtration rate (GFR), which is a crucial indicator of kidney function. When the kidneys are functioning properly, creatinine levels remain relatively stable. However, when there is kidney damage or disease, these levels can rise, signaling a need for further evaluation or intervention.

While the blood urea nitrogen (BUN) to creatinine ratio can also be informative in assessing renal function, creatinine alone is routinely used as a straightforward measure in primary care. Other tests, such as an electrolyte panel, provide less direct information about renal function, and alkaline phosphatase is more relevant to liver function and bone disease. Therefore, creatinine stands out as the primary test used to assess kidney health in a primary care setting.