Renal function refers to the ability of the kidneys to filter blood, remove waste products, and regulate essential substances like water, electrolytes, and acids. The kidneys play a crucial role in maintaining the body's internal balance, ensuring that harmful substances are excreted while vital nutrients are retained. The efficiency of renal function is often assessed through tests that measure glomerular filtration rate (GFR) and the levels of creatinine in the blood. Impaired renal function can lead to conditions such as chronic kidney disease (CKD), which may require medical intervention to manage waste buildup and maintain overall health.