Elevated BUN: Tips on How to Lower it Down

July 22, 2019

What is Blood Urea Nitrogen?

Blood Urea Nitrogen or simply BUN is a blood test used for measuring the urea nitrogen levels in the blood. The result from the test is then used in evaluating the kidney and liver conditions.

The standard measurement used in a BUN test is milligrams per deciliter (mg/dL) in the United States. While international measurement used is in millimoles per liter (mmol/L). To be considered normal, urea nitrogen in the blood should only be within the ranges of 7 to 20mg/dL or 2.5 to 7.1mmol/L.

However, the abovementioned figures are just guides and normal amounts of blood urea nitrogen may depend on the laboratory’s reference range. Normally, the laboratory results also contain the reference range they’d used. The medical practitioner will also base his evaluation of the test results on the persons’ health and other factors. Ask information from your doctor to explain this matter to you.


What is Urea Nitrogen?

The urea nitrogen is a waste product produced in the liver. It occurs when the body cells metabolized protein. It also creates ammonia which contains nitrogen. The urea also includes other chemical compounds such as hydrogen, oxygen, and carbon.

After the formation of urea nitrogen, it travels from the liver through the bloodstream and eventually flushed out from the body via urine.

Properly working kidneys should filter out toxins and waste from the body, which includes urea. A high amount of urea in the blood indicates a damaged liver and/or kidney.


What Causes Elevated BUN (Blood Urea Nitrogen)?

In essence, any disease or disorder that affects the kidneys may also affect how they process toxins and wastes products, which includes urea nitrogen. High levels of urea nitrogen in the blood mean that kidneys filter aren’t working properly. It may signify an existing medical condition that includes:

  • Shock
  • Dehydration – either from poor water consumption or existing medical condition like a fever.
  • Congestive heart failure
  • Heart attack
  • Urinary tract obstruction
  • Bleedings in the gastrointestinal area
  • Excess protein diet
  • Serious burns
  • Particular types of medications that have direct effects on the kidneys, for example, are antibiotics.

Research also found that the amount of blood urea nitrogen tends to increase as we age.

These are only a few examples of what’s causing the presence of high urea nitrogen in your blood. To conclusively identify the problem, consult your doctor.

On the other hand, low production of urea nitrogen can also occur and may indicate some medical conditions. For example, a liver disease or damage limits production of urea. Causes leading to low levels of urea nitrogen may include one of the following:

  • Malnutrition
  • Serious liver condition
  • Low protein consumption
  • Serious muscle tissue damage such as rhabdomyolysis
  • Liver cirrhosis
  • Pregnancy
  • Overhydration or excess consumption of liquids

Males also are shown to metabolized protein differently from children and females. Thus, males are more prone to higher production of urea nitrogen than females and children.


How to Lower Amounts of Urea Nitrogen in the Blood

Enlisted below are a few techniques that can lower urea nitrogen levels in the blood:

Increase fiber consumption

One particular study found that high-fiber foods reduce not only urea nitrogen but also creatinine levels. Examples of foods that contain a high amount of fiber include leafy vegetables, fruits, seeds, and nuts.

Reduce protein consumption

Some health professionals’ advice for people with high levels of urea nitrogen is to limit protein intake. The typical protein intake daily should be within 40 to 60g for adults, and they have to reduce consumption by half to decrease BUN levels. Ask information from your local doctor to know more about how much protein you should take daily. Some examples of foods with high-protein content include red meat, dairy products, poultry meat, fish, grains, beans, and nuts.

Drink plenty of water

Dehydration results in electrolyte and water imbalance within the cells. Thus, the insufficient amount of water in the body causes urea nitrogen levels to increase. Water consumption is particularly important for people with excess fluid loss through physical activities, poor water intake, diarrhea, or taking diuretic medications. While mild dehydration can be treated by increasing water consumption, when dehydration becomes a serious condition, it will not only cause the BUN to peak but may also lead to hospitalization and intravenous fluids.

Learn to cope with stress and manage your high blood pressure

There are a number of cases that involve blood urea nitrogen increase that is caused by unmanaged stress or acute high blood pressure. Many studies have shown that excessive mental pressures can increase blood sugars. Previous studies also linked mental stress to high blood pressure and liver diseases like fatty liver disease. Both high blood pressure and blood sugar can have a significant impact not only on the heart but to the kidneys and liver as well.



Symptoms of a high level of urea nitrogen in the blood may include one of the following:

  • Pain sensation during urination
  • Unusual change in urine coloration which is brown or reddish
  • Foam formation in the urine
  • Swelling in the abdomen, face, legs, or arms
  • Restless feelings in the leg area
  • Joint pains
  • Pain in the back-midsection where the kidneys are located
  • Frequent feelings of tiredness



The doctor may order a blood urea nitrogen if he sees any signs that your kidneys aren’t working properly. He may see these signs during your regular physical examinations.

Before the BUN test, be sure to disclose to your doctor any medications you’re currently taking. This is because certain medications may affect your blood test results. To provide you a conclusive evaluation of your condition, the doctor may request you to stop taking medications for a specific period of time. Other blood test procedures require fasting before the actual test but if you’re ordered only to take BUN test, you may still eat solid foods and drink beverages.

The laboratory technician will take a blood sample from the veins of the arms and/or in the dorsal area of the hands. Results will be provided in a few days, depending on how fast the doctor and laboratory department works.