Commonly Ordered Blood Tests including complete blood count; calcium, phosphorus, and parathyroid hormone; and potassium levels
Blood Urea Nitrogen (BUN) and Creatinine to see whether your kidneys are working properly. If they are not filtering the blood properly, the blood will contain excess amounts of creatinine and urea. Creatinine is a byproduct of muscle function, while urea is a waste product of protein metabolism.
Estimated Glomerular Filtration Rate a measurement of how well the kidneys are processing wastes. Your doctor can calculate the GFR based on gender, age, body size, and blood creatinine level.
The formula used in clinical practice is called the Cockcroft-Gault equation:
Creatinine clearance or GFR (mL per minute) = (140 age) X body weight in kilogram 72 X serum creatinine. If calculated for a female, this product is multiplied by 0.85.The GFR determines the stage of chronic renal disease.
| Stage | Glomerular Filtration Rate (GFR) |
| 1 | over 90 mL/min (normal) |
| 2 | 60-89 mL/min (mild decrease) |
| 3 | 30-59 mL/min (moderate decrease) |
| 4 | 15-29 mL/min (severe decrease) |
| 5 | under 15 mL/min (kidney failure or end-stage renal disease) |
Urine Tests to see if the kidneys are working properly. If they are not working properly, your urine will contain protein. You may be asked to collect urine in a special container over a 24-hour period. This test will also show whether your kidneys are clearing creatinine at a normal rate. The amount of urine you produce is also significant. If your kidneys are failingor starting to failyou may produce little or no urine.
