What is BUN (Blood Urea Nitrogen) in Blood Test? What is High and Low BUN (Blood Urea Nitrogen) Value? Causes & Treatment?
- Health Garden
- Mar 21, 2024
- 3 min read
Updated: Jun 17, 2024
A BUN (Blood Urea Nitrogen) test is a test that measures the number of Urea Nitrogen in your blood.
Ammonia, which is produced as a result of the digestion of proteins, is broken down by the liver and converted into less toxic urea. Urea is a waste product and travels from the liver to the kidneys via the blood to be eliminated from the body. The kidneys filter water-soluble urea from the blood and excrete it from the body as urine.
What is A Normal BUN Value in Blood Test ?
The normal value of BUN in blood test is 7 to 20 mg/dL. Reference ranges may vary slightly between laboratories. The reference value of the laboratory where the test was performed should be taken into account.
BUN values vary depending on age and gender. As we get older, higher levels of BUN are seen in the blood.
Abnormal BUN levels do not always require treatment. Your doctor will evaluate your symptoms and other test results, make a diagnosis, and decide on your treatment.
What is High BUN Value in Blood Test?
A high BUN in a blood test is a value above 20 mg/dL. High urea is usually related to the kidneys. However, high urea may also occur for other reasons.
What Causes High BUN in Blood Test?
High urea usually indicates that the kidneys are not working well. However, it is not possible to say that the kidneys are not functioning well just with a high BUN value. Your doctor will also evaluate other blood parameters for an accurate diagnosis. Apart from this, other reasons that may cause high urea are:
Urinary tract obstruction
Congestive heart failure or recent heart attack
Dehydration (too little fluid in the body)
Severe burns
Some drugs
High protein diet
Age
High BUN Symptoms
Symptoms that may occur with high urea are as follows:
Thinking and memory problems
Fatigue
Dyspnea
Loss of appetite
Muscle cramps
Nausea and vomiting
Itching
Sleep disorders
Mouth dry
Ammonia smell on breath
Irrepressible hiccups
Unexplained weight loss
In cases where urea levels are too high, in addition to the above symptoms, symptoms such as urine-like odor in the breath, metallic taste in the mouth, and the formation of yellow or white crystals on the skin may also occur.
How to Treat High BUN Level?
High urea is caused by many different disorders, and the treatment of high urea depends on the underlying cause. If there is more than one cause of high urea, it is important to treat it with a multidisciplinary approach. If there is high urea due to advanced renal failure, patients may be treated with dialysis. However, the reason for high urea may sometimes be due to a diet containing high protein or consuming less water. In such cases, treatment methods such as changes in diet or reducing water consumption to normal levels are planned. By applying these treatment methods, it is aimed to bring the urea level in the blood to normal levels.
What is Low BUN in Blood Test?
Low BUN in a blood test is a value below 7 mg/dL. Low urea in the blood is a rare condition. It mostly occurs with irregular and malnutrition.
What Causes Low BUN in Blood Test?
Some possible factors that cause low BUN include:
Liver diseases
Protein deficiency due to inadequate and irregular nutrition
Pregnancy period
Excessive water consumption
Use of certain medications
Diseases such as Crohn's disease, Zollinger Ellison Syndrome (ZES) and pancreatic insufficiency
Low BUN Symptoms
Symptoms of low urea, which is not as common as high urea, are usually experienced due to the underlying disease. Although it usually occurs due to triggering diseases, common symptoms of low urea are frequent urination and foaming of the urine.
How to Treat Low BUN Level?
Blood urea level being below normal values is a rare condition and is mostly due to malnutrition. If the underlying cause of low urea is malnutrition and excessive water consumption, the specialist aims to increase the urea level by arranging a diet suitable for the patient. However, if there is a different underlying cause, low urea can be prevented by eliminating the disorder causing low urea, with a multidisciplinary approach when necessary.