The normal value for serum creatinine can range from 0.7-1.2 mg/dL (62–106 μmol/L). Gastrointestinal bleeding, due to the proteins present in the bloodĭecreased BUN is less common.Decreased blood flow to the kidneys, such as in congestive heart failure, shock (severe low blood pressure), burns, severe heart attack, and dehydration.Acute or chronic kidney disease, damage, or failure, such as those caused by diabetes and high blood pressure.The normal value of BUN can range from 7 – 20 mg/dL. The normal range for BUN, serum creatinine vary among laboratories. Photo Source: What Do the Test Results Mean? Picture 2: Blood being withdrawn from a vein in the arm. Drink enough water during the 24 hours prior to the test. Do not eat more than 8 oz (227 g) of meat or other protein-rich food for 24 hours prior to the test. ( 6) For Serum Creatinineĭo not exercise strenuously for 2 days (48 hours) prior to the test.

How should you prepare for the tests? For BUNĭo not eat too much meat or other protein-rich food for 24 hours prior to the test. Monitoring the effectiveness of dialysis ( 4, 5).Monitoring of kidney function in patients with chronic diseases such as diabetes, congestive heart failure, and heart attack.Monitoring of kidney function before starting on particular drug treatments.Confirmation of suspected kidney disease.Acutely ill patients that come to the emergency room and/or is admitted to the hospital.( 4, 5) When are the tests ordered?īUN and serum creatinine may be ordered as part of the basic metabolic panel (BMP) or comprehensive metabolic panel (CMP), which are sets of tests ordered in: It is particularly useful in differentiating acute and chronic kidney disease. ( 3) Why are BUN, Serum Creatinine, and BUN/Creatinine Ratio Assessed?īUN and serum creatinine are commonly assessed together to evaluate kidney function, to diagnose kidney disease, and to monitor patients with acute or kidney disease.īUN/creatinine ratio is useful in determining the more specific causes of abnormalities in the levels of BUN and serum creatinine. ( 2) BUN/ Creatinine RatioīUN/creatinine ratio is the ratio of BUN to serum creatinine. Creatinine is freely filtered but not reabsorbed in the kidneys. It is released in the blood, and eventually reaches the kidneys for excretion through the urine. Creatinine is a waste product produced by the muscles during the metabolism of creatine phosphate, a substance involved in energy production in muscles.Ĭreatinine is produced at a relatively constant rate every day, depending on muscle mass, which is relatively unchanged from day to day. Serum creatinine is a laboratory test that measures the amount of creatinine in the blood. Urea is freely filtered and reabsorbed by the kidneys. Urea is released by the liver into the blood, and eventually reaches the kidneys for excretion through the urine. Protein metabolism produces ammonia, which is eventually converted to the less toxic waste product, urea. Why are BUN, Serum Creatinine, and BUN/Creatinine Ratio Assessed?.

Normal range for bun levels