Kidney Function Tests are a group of blood and urine tests used to evaluate the performance of the kidneys, which are responsible for filtering waste products and excess fluids from the body. These tests help diagnose kidney diseases, monitor chronic kidney conditions, and assess kidney function before certain medical treatments or surgeries. The key tests used to assess kidney function include: 1. Serum Creatinine: Creatinine is a waste product generated from muscle metabolism, and it is filtered out of the blood by the kidneys. Elevated serum creatinine levels indicate that the kidneys may not be filtering properly, which can be a sign of kidney damage or disease. 2. Blood Urea Nitrogen (BUN): BUN measures the level of urea, a waste product formed from the breakdown of protein in the body. High BUN levels can suggest impaired kidney function, dehydration, or excessive protein intake, but they can also be influenced by other factors such as gastrointestinal bleeding or heart failure. 3. Glomerular Filtration Rate (GFR): GFR is an important test that estimates how well the kidneys are filtering blood. It is calculated based on serum creatinine levels, age, gender, and race. A GFR below 60 mL/min/1.73m² for three months or more indicates chronic kidney disease (CKD). These tests, along with clinical symptoms and imaging studies, help healthcare providers detect early signs of kidney disease, determine its severity, and guide treatment to preserve kidney function and prevent complications.