It comes from creatinine, a protein that helps generate energy for muscle contraction and is transported through the bloodstream to the kidneys, where it is filtered and excreted through the urine. What Is a Creatinine Test?Ĭreatinine is a type of molecule or waste product that is generated from muscle wear and tear. High levels of urea may be a sign of some kidney problem that needs medical attention. Having some urea in the blood is normal as the liver is constantly producing it.

Optimal functioning kidneys then filter and remove other waste products like urea through urination. The nitrogen comes from the waste product urea converted from nitrogen and produced in the liver when protein is metabolized after eating. It allows the doctors to learn about your kidney and liver performance. In most cases of chronic renal or kidney damage, this ratio stays relatively normal.Ī Blood Urea Nitrogen (BUN) test measures the amount of nitrogen in your blood.When there is a decline in the formation of urea, the ratio of BUN/Creatinine also goes down.Increased urea formation can also increase the ratio, such as gastrointestinal bleeding and trauma, etc.Reduced kidney perfusion such as congestive heart failure or recent onset of urinary tract obstruction can lead to an increase in the BUN/Creatinine ratio.The BUN/Creatinine ratio helps with differential diagnosis of acute or chronic kidney disease.Some essential factors to know about BUN/Creatinine blood test

When the BUN levels are studied with the creatinine levels, it gives a better picture of what is happening with the kidneys. It is the reason a creatinine test is also needed. The BUN level alone does not reveal much about kidney health. It allows the healthcare providers to assess how well the kidneys are functioning. Together, they help in measuring the overall kidney function. They can also determine gastrointestinal bleeding or trauma in some cases.īlood urea nitrogen and creatinine are both filtered in the kidney and excreted in the urine. And while they can be tested separately, the BUN/creatinine ratio can help pinpoint significant health issues. These tests reveal a lot about your metabolism, kidney, liver, and overall health. What Is a Bun/Creatinine Ratio Test?īUN (blood urea nitrogen) and creatinine are two blood tests used for diagnosing acute or chronic kidney damage or disease.

The internal medicine doctors at the Century Medical and Dental Center focus on diagnosing your renal problems and use the test results to recommend the best treatment. The BUN/Creatinine ratio blood test measures the overall kidney functions and detects any sign of metabolic disease or liver damage. If you have a family history of kidney disease or suffer from diabetes and high blood pressure, get your BUN and creatinine ratio tested as urea and creatinine are filtered in the kidney and excreted in the urine. We concluded that the normal range of BUN and Cr levels differed between young and elderly subjects, and that the decline in renal function correlated with age after the seventh decade.Early kidney disease is a silent problem, and you may not know about it until you begin to feel the symptoms and it is too late to reverse it. Although Cr levels did not correlate with age in elderly subjects, Cr levels divided by body surface area significantly correlated with age. Significant positive correlation was found between BUN levels and age in male elderly subjects. The mean Cr level in the elderly subjects was slightly higher than that in the control subjects. The mean BUN level in the elderly subjects was significantly higher than that in the control young subjects. The estimated normal range of BUN was 14-23 mg/dl both in male and female elderly subjects, and that of Cr was 0.9-1.3 mg/dl in male and was 0.7-1.1 mg/dl in female. We defined the normal range as range within the single SD-line of the remainder. We calculated the mean and the standard deviation (SD) in each group, and excluded subjects with values beyond twice the SD-line. This study was a part of the Kahoku Longitudinal Aging Study (KLAS) that aims to reveal the comprehensive functions in the aged. We measured the variables also in 315 cases of sex-matched young control subjects (male, 139 female, 176). To estimate normal ranges of blood urea nitrogen (BUN) and serum creatinine (Cr) levels in the aged, we measured BUN and Cr levels in 332 cases of apparent-healthy elderly subjects (male, 152 female, 180) aged 70 years or more.

Bun creat normal range