BUN Creatinine Ratio: Understanding Its Importance & Normal Range

The kidney is an important organ in the human body. Its key functions include filtration of toxins and waste products. 

Any abnormality may lead to kidney disease or kidney failure. A study found that around 17% of Indians have chronic kidney disease (CKD). However, the number varies in every region. 

This ratio can be curbed with early detection of kidney functionality. Early detection helps plan effective disease management and treatment. 

BUN creatinine ratio is a calculated formula that determines kidneys' functionality in filtering waste products. Today’s blog will provide blood urea nitrogen meaning, its normal range, and BUN creatinine ratio. 

Understanding BUN Creatinine Ratio

When your kidney fails to work properly, your healthcare provider may recommend a creatinine test and a blood urea nitrogen (BUN) test. These two tests are essential for monitoring your kidney function. A BUN creatinine ratio is a critical marker for kidney health. 

Experts recommend that you should take tests from a reliable diagnostic service provider. Redcliffe Labs is a leading omnichannel PAN India diagnostic laboratory, offering over 3600 quality diagnostic tests at affordable prices. To make diagnostics even more accessible, they provide a home sample collection service. After booking tests, their DMLT-certified phlebotomist will visit your home for sample collection. 

They offer the blood urea nitrogen (BUN) and creatinine tests at INR 149 and 140, respectively. 

BUN Test 

BUN, or blood urea nitrogen test, is a blood test. The test measures the amount of urea in your blood. Urea nitrogen is the waste compound your liver utilizes from the protein in your foods. This protein collapses to create BUN. 

A doctor may recommend the BUN test: 

• For assessing dehydration 
• For monitoring, medication effects
• For evaluating liver function
• As a part of a routine health check-up
• To check your kidney functioning 
• For evaluating symptoms of kidney disease 

Symptoms of Abnormal BUN Levels

The symptoms of abnormal BUN levels differ depending on whether the level is high or low. Here are some common symptoms related to abnormal BUN levels. 

High BUN Levels

• Swelling in ankles or legs 
• Fatigue 
• Changes in urination 
• Itchy skin 
• Nausea and vomiting 

Low BUN Levels 

• Weakness 
• Swelling or Edema
• Nutritional deficiencies 
• Mental confusion 
• Gastrointestinal Issues 

Creatinine Test

A creatinine test is a simple blood test that measures creatinine levels and assesses kidney functioning. Creatinine is a protein that produces energy for muscle contraction. Your kidney filters it out from the blood and then eliminates it through urine. 

Why can your doctor recommend the Creatinine Test? 

A doctor can recommend a creatinine test to screen for kidney disease. They can also recommend the test if you have diabetes, high blood pressure, or other medical conditions. 

Symptoms of Abnormal Creatinine Levels 

The symptoms of abnormal creatinine and BUN levels are similar, which can be associated with other medical conditions. 

• Swelling 
• Fatigue 
• Nausea 
• Vomiting 
• Shortness of breath 

Also, read https://redcliffelabs.com/myhealth/health/control-your-creatinine-levels-with-these-5-best-foods/ 

What is the Blood Test BUN Creatinine Ratio? 

A blood test BUN creatinine ratio compares blood urea nitrogen (BUN) levels to creatinine in the blood. It is a routine screening test that helps detect kidney disease and other underlying health issues. 

BUN test results can be normal, lower, or higher. The low and high ranges indicate underlying health conditions. 

The normal range of BUN creatinine ratio is between 10:1 and 20:1. It is a better indicator of kidney health than BUN or creatinine levels alone. 

The high BUN ratio indicates congestive heart failure, gastrointestinal bleeding, and dehydration. Meanwhile, the low BUN ratio indicates malnutrition or liver disease. 

What is the BUN Creatinine Ratio Calculator? 

The BUN creatinine ratio calculator assesses kidney function by comparing the levels of creatinine and BUN in the blood. 

Through this method, doctors can determine the efficiency of your kidney to filter out waste products from the blood. The BUN creatinine ratio also helps identify any underlying abnormalities. 

The steps to assess the BUN creatinine ratio are simple. 

• Get a BUN and creatinine blood test and their values in your blood. 
• Ensure that the measurements of the BUN and creatinine units match. The unit is milligrams per deciliter (mg/dL).
• Divide the BUN value by the creatinine value with the BUN creatinine ratio formula. 
• The formula is: 

BUN Creatinine Ratio = BUN (mg/dL) / Creatinine (mg/dL) 

For example: 

If your creatinine value is 1 mg/dL and BUN value is 20 mg/dL. The calculation would be: 

BUN creatinine ratio = 20 mg/dL / 1 mg/dL = 20. 

So, your BUN creatinine ratio is 20. 

BUN Creatinine Ratio Normal Range 

A normal bun creatinine ratio typically falls between 10:1 and 20:1. The BUN creatinine ratio differs by age and gender. Here is a detailed BUN creatinine ratio chart for every age and gender. 

Blood Urea Nitrogen (BUN) Levels
Age	Male (mg/dL)	Female (mg/dL)
< 1 month	4-12	3-17
1 month to 11 months	2-13	4-14
1 year to 3 years	3-12	3-14
4 years to 19 years	7-20	7-20
20 years and above	7-25	7-25
Creatinine Levels
Age	Male (mg/dL)	Female (mg/dL)
2 days or below	0.79- 1.58	0.79- 1.58
3-27 days	0.35-1.23	0.35-1.23
1 month to 9 years	0.20-0.73	0.20-0.73
10 years to 12 years	0.30-0.78	0.30-0.78
13 years to 15 years	0.40-1.05	0.40-1.00
16 years to 17 years	0.60-1.20	0.50-1.00
18 years to 19 years	0.60-1.26	0.50-1.00
20 years to 49 years	0.60-1.35	0.50-1.10
50 years to 59 years	0.70-1.25	0.50-0.99
60 years to 69 years	0.70-1.25	0.50-0.99
70 years to 79 years	0.70-1.18	0.60-0.93
80 years or above	0.70-1.11	0.60-0.88

Factors Affecting BUN to Creatinine Ratio 

The BUN creatinine calculator easily measures the BUN creatinine ratio. However, certain factors before the BUN and creatinine tests can affect the ratio. These include: 

• Your diet 
• Medications such as corticosteroids, antibiotics, and diuretics 
• Liver disease 
• Sickle cell anemia 
• Kidney damage 
• Pregnancy 
• Metabolic disorders 
• Rhabdomyolysis 
• Your age 
• Hydration level 

Causes of BUN Creatinine Ratio Low 

A low BUN creatinine ratio can occur due to various health conditions. These include low protein intake, malnutrition, certain conditions affecting muscle mass, overhydration, and liver disease. 

Causes of BUN Creatinine Ratio High 

A high BUN creatinine indicates kidney damage, disease, or dysfunction. If your BUN creatinine levels are elevated, it can be a sign of low kidney filtration ability or impaired blood loss in the kidney. To clearly understand, your doctor may recommend further diagnostic tests to identify the underlying health issue and plan the management and treatment accordingly. 

10 other causes of the high BUN creatinine ratio include: 

• Stress
• Burns
• Dehydration 
• High-protein diet 
• Pregnancy 
• Heart attack 
• Inability to pee because of a blockage in the urinary tract 
• Gastrointestinal bleeding 
• Age 
• Certain medicines, including steroids and antibiotics

Also, read https://redcliffelabs.com/myhealth/health/how-to-reduce-creatinine-levels/

What Do Low BUN Levels Mean?

Low BUN levels are uncommon and, in most cases, aren't a cause for concern. However, severe health conditions can cause BUN levels to be unusually low.

A low BUN level may be normal during the second or third trimester of pregnancy. They could also indicate:

• Overhydration
• Liver failure
• Severe lack of protein 
• Malnutrition

What Do High BUN Levels Mean?

A BUN level over 20 mg/dL is considered abnormal and can point to some harmful conditions. But a dangerously high BUN level, often starting at 50 mg/dL, indicates kidney damage that needs immediate medical attention.

A patient with a BUN between 100 mg/dL and 250 mg/dL may have severe kidney dysfunction, resulting from a problem with the organ's ability to filter waste products out of the bloodstream.

A high BUN level typically indicates some dysfunction with a patient's kidneys. This can be caused by:

• Certain medications 
• Dehydration
• Urinary tract obstruction
• Congestive heart failure
• Recent heart attack
• Gastrointestinal bleeding
• Shock

What level of BUN indicates kidney failure?

Health care providers typically don't rely solely on blood urea nitrogen (BUN) levels to diagnose kidney failure. 

However, if a patient's BUN levels exceed their normal baseline and their creatinine levels are elevated, it indicates potential kidney failure. 

A BUN level higher than 20 mg/dL suggests that the kidneys may not be functioning at optimal capacity.

Key Takeaways 

The BUN creatinine ratio is essential for diagnosing and managing various liver and kidney diseases. The BUN test and creatinine test both equally support kidney health. Take the blood urea nitrogen (BUN) and creatinine tests from Redcliffe Labs. Measure the values and take preventive measures to ensure overall well-being. 

Frequently Asked Questions (FAQs)

Q1. What is BUN in a blood test used for?

Ans: It helps assess kidney and liver function, hydration status, and protein metabolism.

Q2. What does a high BUN Creatinine Ratio mean?

Ans: It may indicate dehydration, internal bleeding, or heart failure, even if creatinine levels are normal.

Q3. What causes a low BUN Creatinine Ratio?

Ans: It may be caused by liver disease, a low-protein diet, or excess fluid intake.

Q4. Can medications affect BUN and creatinine levels?

Ans: Yes. Diuretics, NSAIDs, ACE inhibitors, and some antibiotics can impact kidney filtration.

Q5. Should I fast before a BUN blood test?

Ans: Fasting isn't usually required unless combined with other tests. Always follow your doctor's instructions.

Q6. Can diet alone fix an abnormal ratio?

Ans: Diet plays a role, but it's essential to identify and treat the underlying cause with a doctor's help.