What is the BUN Creatinine Ratio?
Blood Urea Nitrogen (BUN) and creatinine are the waste products produced by the body filtered through the kidneys from the blood, and excreted from the body in the urine. The Blood Urea Nitrogen to Creatinine ratio is a diagnostic test that evaluates the functioning of the kidney along with the hydration status.
Blood Urea Nitrogen (BUN) measures the levels of nitrogen present in the blood as a result of the byproduct of protein metabolism in the liver namely urea.
Creatinine is the waste product produced by the muscle tissue breakdown and filtered at a constant rate through the kidneys.
The diagnostic test BUN Creatinine ratio measures the filtering efficiency of kidneys. An elevated or lowered ratio indicates various health issues, such as kidney disorders, diseases associated with liver disorders, and dehydration. For the evaluation of the overall health and kidney function, this test is often recommended as a part of the comprehensive metabolic panel (CMP).
How is the Test Performed?
A simple blood draw is performed using the process of venipuncture for the BUN creatinine ratio test and then analyzed in the laboratory.
Preparation
- Avoid eating meat for at least a day before the test.
- Keep yourself hydrated as the hydration status may affect the test ratio.
- Inform your doctor about any medication as he might adjust the dosage of certain medications such as NSAIDs, anti-inflammatory medicines, etc. that might affect the test results.
The blood test is usually conducted in the morning as the metabolic levels and status of hydration of the body are most stable at that time of the day.
What are the symptoms that prompt this test?
Your healthcare provider may recommend this test to individuals exhibiting the signs and symptoms of metabolic disorders, dehydration, liver dysfunction, and kidney disorders;
Symptoms Associated with Kidney Disorder
- Changes in urine appearance
- Edema
- Painful urination
- Presence of blood in urine
- Nausea and vomiting
- High blood pressure
- Difficulty breathing
- Persistent fatigue
Symptoms Associated with Dehydration
- Fast heartbeat
- Skin dryness
- Decreased urine output
- Dark urine
- Increased thirst
- Lethargy
General Symptoms
- Weight loss without a known reason
- Muscle cramps
- Appetite loss
What are Normal Ranges for This Test?
The generally accepted reference range for the BUN creatinine ratio is mentioned below however it may vary according to the assay of the test used by the laboratory.
- Normal – 10:1 to 20:1
- High – More than 20:1
- Low – Less than 10:1
**The values above are general guidelines only. Always consult your healthcare provider for the correct interpretation of the results according to your health condition. **
What Happens if Test Results Show Abnormal Levels?
Abnormal levels of BUN Creatinine Ratio indicate an underlying condition that needs early medical treatment for better disease management.
A High BUN Creatinine Ratio indicates
- Dehydration
- Gastrointestinal bleeding
- High protein diet
- Heart failure
A low BUN Creatinine Ratio indicates
- Severe injury of muscles
- Low protein intake
- Liver dysfunction
If abnormalities are diagnosed further testing is suggested along with medications and lifestyle changes such as balanced intake of protein, surgery to stop gastrointestinal bleeding, and incorporating physical therapy for the management of muscle injuries.
