Brief summary: 

BUN is blood urea nitrogen. Creatinine is a natural product of basic muscle breakdown. The kidney filters these and releases it in the urine. So they help to measure kidney function 

 

Technical purpose: 

It is useful to check if kidneys are functioning properly, diagnose acute or chronic renal disease such as congestive heart failure, the onset of UTI, gastrointestinal bleeding, etc.

 

Test Process: 

A sample of blood is collected from the elbow pit for BUN. No preparation is required prior to the test. And creatinine can be measured by a urine test. And the ratio is calculated 

 

Test Outcome:

The normal levels depend on muscle mass and age. In general it is, 0.5 to 1.2 milligrams per deciliter (mg/dL).The normal BUN is 7 to 20 mg/dL. And the normal ratio is between 10 to 1 and 20 to 1. 

 

Sources:

https://www.dovemed.com/common-procedures/procedures-laboratory/bun-creatinine-ratio-blood-test/

https://www.medicinenet.com/creatinine_blood_test/article.htm