Introduction to BUN Levels
BUN stands for blood urea nitrogen. Urea is a waste compound that results from the metabolism (breakdown) of ingested proteins from your diet and protein released from your tissues; since urea forms in your liver and is later excreted through your kidneys, a BUN test can be useful to evaluate the function of your kidneys when used along with other tests. However, it is important to note that BUN levels can be affected by several factors; therefore, a BUN test should not be used as a stand-alone measurement to diagnose or assess kidney disease.
Nevertheless, consistently high BUN levels can indicate an underlying condition, necessitating collaboration with your doctor to identify the cause and devise a treatment plan. In addition to medical intervention, adopting a healthy lifestyle, ensuring adequate hydration, consuming a balanced low-protein diet, prioritizing rest, managing stress, and employing coping techniques may aid in lowering BUN levels.
What is BUN?
Blood urea nitrogen, also known as BUN, is a test that can be useful to determine the health of your kidneys when used in conjunction with other tests, such as creatinine. A BUN test measures the nitrogen component of urea, which is a waste by-product of protein breakdown that forms in the liver and travels through your bloodstream to your kidneys, where it gets released through your urine. (1, 2)
What is a Normal BUN Range?
Generally, the normal level of BUN ranges from 6 to 20 mg/dl; however, these values may vary slightly depending on the laboratory and the method used for testing. (3, 4)
What Can Cause Elevated BUN Levels?
High BUN levels can happen for several reasons, such as: (3, 5-10)
- Increased protein intake from your diet
- Dehydration
- Stress
- Strenuous exercise
- Chronic kidney disease (CKD)
- Acute kidney injury (AKI)
- Fever
- Infections
- Tumors of the urinary tract
- Heart problems (such as severe congestive heart failure or a recent heart attack)
- Bleeding from the gastrointestinal tract
- Pregnancy
- Severe burns
- Use of certain drugs like corticosteroids and some antibiotics
What are the Symptoms of High BUN levels?
Since high BUN levels can happen for many reasons, you may experience several symptoms or none at all, depending on the specific cause and the timeframe since you first started experiencing high BUN levels. However, if you do experience symptoms, these may include: (8, 11, 12)
- Frequent need to urinate
- Constantly waking up at night to urinate
- Foamy urine
- Bloody urine
- Difficulties or burning sensation when urinating
- Fatigue
- Loss of appetite
- Muscle cramps
- Numbness and/or swelling, especially in your limbs
- Constant pain in your flank areas
- Unintended rapid weight changes, either loss or gain, can occur
What Health Problems are associated with High BUN Levels?
In a population study, higher BUN levels correlated with increased diagnosis of Diabetes Mellitus. However, this may be subject to other influencing factors, which need further research to clarify. (13)
In critically ill people who have been admitted to ICU (intensive care unit) and in people who need to undergo heart surgery, high BUN levels have been associated with an increased mortality rate and stroke risk. (14-16)
What Can I Do to Lower My BUN Levels?
The first thing to do is to pinpoint the cause of your high BUN levels. As previously discussed, there are a lot of things that can cause your BUN levels to increase, so in order to keep them within a normal range, you need to work with your doctor to find and address the cause of the issue. Knowing this, let us take a deeper look into the specific things you can do to keep your BUN at a normal range:
1. Rule out Medical Problems
Since high BUN levels can indicate either acute (sudden) or chronic (long-term) kidney issues, your healthcare provider will indicate other lab tests to assess your renal function. If you have kidney problems, then you need to work with your doctor to address this issue. The main goal of managing increased BUN levels is to prevent further damage to your kidneys and to improve your overall renal function.
However, if you do not have kidney problems but your BUN levels remain high, your doctor may indicate other lab tests and/or imaging studies to diagnose or rule out any other medical condition that may be causing your BUN levels to rise.
2. Keep an Eye on your Medications and Supplements
Certain drugs can cause BUN levels to rise. Make sure to tell your doctor about any drugs you are taking and whether you have recently changed your dosage or intake frequency. Your doctor may adjust the dosage or change your medication to help lower your BUN levels.
Some of the most frequent drugs that may cause abnormal BUN levels include: (17)
- Chloramphenicol
- Streptomycin
- Cephalexin
- Rifampin
- Amphotericin B
- Penicillin
- Gentamicin
- Vancomycin
- Diuretics, such as furosemide, spironolactone, and hydrochlorothiazide
- Non-steroidal anti-inflammatory drugs (NSAIDs), such as ibuprofen, aspirin, and naproxen
- Lithium
- Carbamazepine
- Celecoxib
- Methotrexate
On the other side, herbal supplements and even natural diuretics (such as caffeine) can also cause damage to the kidneys, especially in people with kidney disease. Furthermore, since herbal supplements are not regulated by the U.S. Food and Drug Administration (FDA), it is difficult to ascertain the effective dosage and effectiveness of these supplements; besides, herbal supplements can even contain certain compounds, like heavy metals, that can cause direct damage to the kidneys. (19)
3. Make Sure to Get Enough Hydration
Inadequate water intake is one of the common reasons for an isolated BUN increase in an otherwise healthy person, in the context of a normal creatinine.
Several studies recommend approximately three liters of water per day in males, and two to two and a half liters in females. However, this is highly variable among people, depending on factors such as daily activities. Moreover, healthy people are able to regulate their water intake by their thirst mechanism. (20-21)
4. Reduce Your Dietary Protein Intake
Excessive dietary protein intake is another frequent reason for BUN levels to increase; therefore, a low-protein diet can help lower your BUN levels. (22)
Foods that are high in protein, meaning that you should avoid or limit their intake, include:
- Meats (poultry, beef, fish, pork)
- Dairy products (milk, cheese, yogurt -especially Greek yogurt-)
In some cases, the intake of protein supplements, such as whey protein powder or similar products, can increase your BUN levels. In this case, all you need to do is to adjust your protein dosage according to your daily needs. Your daily goal should be to consume a maximum of 0.028 oz (0.8 grams) of protein per 2.2 lb (1 kilogram) of your body weight. (23)
It is important to bear in mind that this recommendation may vary according to the daily physical activity. You should talk to your doctor or dietician to find the appropriate amount for you.
You can also try to increase your daily intake of high-fiber, low-protein foods, which include fruits, vegetables, grains, non-sugary cereals, and healthy fats like nuts and avocados, as part of a healthy diet.
5. Reduce Your Stress Levels
Stress induces the release of a hormone called cortisol in the body, which in turn can contribute to an increase in BUN levels.
You can try different alternatives and approaches to keep your stress under control. Good options include breathing exercises, meditation, exercise, and mindfulness. If you are under constant stress in your daily life, and you feel you canāt get it under control, you should consider talking to a licensed therapist or counselor who can provide you with the right tools to help you manage your stress levels. (24)
6. Get the Right Amount of Exercise
Exercise is a great way to lower your stress levels, which in turn helps keep your BUN levels at a normal range. The American Heart Association recommends 150 minutes of weekly aerobic exercise, which can be split into sessions of 30 minutes five days a week. (25)
However, excessive exercise can be counterproductive to lower your BUN levels as it can put your body in a constant state of physical stress, leading to muscle soreness, mood changes, and sleep difficulties, especially when you are overtraining and not eating enough, and/or not allowing enough time for your body to recover in between training sessions.
See Also
What are the Creatinine Lab Values
What are the Normal Lab Values
Grants for Laboratory Equipment
