Blood urea nitrogen and blood urea are two different medical tests that are a part of any regular and normal health screening process. BUN or blood urea nitrogen measures the entire volume of urea nitrogen present in blood. On the other hand, blood urea is an investigation of the entire concentration of urea present in blood as it is produced during the urea cycle of the liver. However, BUN and blood urea are not one and the same thing. There are several differences between the two, and here’s outlining all the related details.
What exactly is blood urea nitrogen (BUN)?
The blood urea nitrogen or serum BUN test focuses on investigating and assessing the amount of wastage present in the blood. The test is helpful in determining how well the kidneys work. Doctors use this test to diagnose, screen, and monitor any issues related to the kidneys. So, doctors can suggest this test in the following cases:
- to test the symptoms related to kidney diseases like predominant fatigue
- to monitor how the condition of a patient changes
- to detect health issues right before the symptoms show up
If the test indicates that the BUN levels are excessively high, it’s an indication that kidney functions are not working properly. High BUN levels are triggered by reduced blood flow to kidneys. Reduced blood flow to kidneys results from either dehydration or heart failure.
What exactly is urea?
Blood urea refers to the urea concentration found in the blood. So, urea is basically a type of waste that is formed in the liver and gets excreted from your body as urine. When kidneys don’t work properly for some reason and can’t get rid of all the waste in urea naturally from the blood, the level of BUN rises.
Higher BUN levels can also be caused by other complications, such as a high protein diet or dehydration. Blood urea level can increase due to muscle injury or higher catabolic rate. It lowers because of liver damage or might be used in anabolic reactions. As such, blood urea is an assessment of whether an individual is healthy or not.
Here are some of the tips to reduce blood urea levels:
- lower the salt intake
- avoid alcohol and smoking
- increase your fiber intake
- avoid overuse of NSAIDs
- reduce your daily protein intake
Moreover, an increased catabolic rate or higher muscle breakdown or reduced rate of glomerular filtration in the kidneys and the reduced blood volume can lead to elevated blood urea nitrogen. On the other hand, lower levels of blood urea nitrogen is noted when the liver starts malfunctioning. The same thing happens during muscle mass formation or an increase in anabolic reactions. Thus, blood urea nitrogen level is typically lower in kids than that of adults.
Similarities between blood urea nitrogen and urea
There are top six similarities between blood urea and blood urea nitrogen:
- Both offer insights to the catabolism, muscle anabolism, and muscle building rate
- They are an indication of malnutrition conditions, reduced protein diets, or accelerated muscle breakdown.
- Both these factors are assessed in mg/dL.
- Daily dietary intake of protein shows a major and direct impact on both the components.
- Regulation and occurrence of the urea cycle are crucial for both these measurements.
- They offer a complete idea of nitrogen metabolism that includes both anabolic and catabolic reactions.
Differences between blood urea nitrogen and urea
There are several differences between blood urea nitrogen and urea, and they are:
Definition –
In blood urea, the measurement focuses on the amount of urea that is found in blood. On the other hand, the nitrogen content in urea is assessed in BUN test. The regular BUN level remains between seven and twenty mg/dL.
Symptoms –
Increased BUN levels can lead to the following symptoms:
- Vomiting
- Muscle cramps
- Confusion
- Recurring fatigue
- Tachycardia
- Itching
- Uremic frost
- Anasarca or edema
- Swelling in your feet, legs, or arms
- Pale skin coloration
- Sleep disorder or disturbed sleep
- Anuria or oliguria
- Urge to infrequently or frequently urinate
- Dehydration
Decreased BUN levels can show the following two symptoms:
- Wasting syndrome
- Jaundice
Increased urea levels can lead to the following symptoms:
- Headache
- Shortness of breath due to fluid accumulation
- Difficulty in concentrating
- Sudden weight loss
- Cognitive dysfunction (issues related to remembering and thinking)
- No or little appetite
- Vomiting
- Leg Cramping
- Extreme sleepiness
- Altered taste
- Nausea
- Extreme fatigue or tiredness
Kidney involvement –
In the case of blood urea, kidneys aren’t involved. But in the BUN test, the kidneys are involved because it is an indication of kidney injury or dysfunction.
The bottom line
Whether you need a BUN test or blood urea test depends on your health needs. Your doctor will determine which test you need as per your health conditions. They might even order both the tests to get the right results.
