Blood urea nitrogen (BUN) and creatinine are lab values that Dietary Protein, BUN and Creatinine: What's the Connection? . Receive tips from dietitians to help you understand and manage all aspects of the kidney diet. Normally, your kidneys screen impurities from your bloodstream. The result of this process is the removal of waste materials and excess fluid in the urine. Two laboratory blood tests that measure kidney function are creatinine and blood urea nitrogen, or BUN. Both tests are related and are associated with the.
Helen Messina Medical technician holding a blood test Image: The result of this process is the removal of waste materials and excess fluid in the urine. Occasionally, infections, injuries and disease hamper the ability of the kidneys to perform this process, resulting in renal insufficiency. To confirm a suspicion of renal insufficiency requires evaluating test results together with signs and symptoms to make a final diagnosis. Two important tests are the blood urea nitrogen, or BUN, and the serum creatinine.
Serum Creatinine Creatinine, a waste material, comes from the breakdown of protein in your body. The kidneys filter out the creatinine and eliminate it in the urine. The portion of the kidneys that filters out the creatinine, called the glomerulus, is susceptible to blood vessel problems and infections that cause more creatinine to build up in the bloodstream.
Dietary Protein, BUN and Creatinine: What's the Connection? - Kidney Diet Tips
The serum creatinine blood test measures the amount of creatinine in the bloodstream when the kidneys are unable to remove it.
An elevated serum creatinine reliably reflects renal insufficiency but is taken into consideration with the urine creatinine clearance and blood urea nitrogen. Blood Urea Nitrogen Urea nitrogen comes from protein intake and the breakdown of protein in tissues.
Patients with little or no kidney function will have very high blood levels of creatinine. Artificial kidneys are used in a process called dialysis to filter out toxic levels. Low levels of creatinine are found in conditions that cause decreased muscle mass. Decreased levels are temporarily found in pregnancy as well. Simple dehydration can cause an elevated BUN level.
The BUN level is primarily used to monitor kidney function or to obtain a baseline before certain drug therapies are started.
Diseases and conditions that result in an elevated abnormal blood urea nitrogen level can include high-protein diets, high blood pressure, chronic diseases, diabetes, heart failure and heart attack.
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Decreased levels of BUN can indicate liver failure and malnutrition. Vegetarians may have a low BUN, but a low level is considered normal in vegans. The reference ranges for each test as well as the ratio between the two tests are posted along with the test results.
The reference ranges tell the doctor whether or not the result is normal or abnormal. An increased ratio of BUN to creatinine may be due to conditions that cause a decrease in the flow of blood to the kidneys, such as congestive heart failure or dehydration.
It may also be seen with high protein blood levels or from gastrointestinal bleeding. A decreased ratio may be observed with liver disease and poor diet. Temporary levels that are high or low may not be a cause for concern and should be retested to confirm.
Treatment Dialysis is used to filter the blood when the kidneys are not functioning properly.