There are often kidney friends with the laboratory test is very nervous question, their urea nitrogen (BUN) is high, is it a problem of kidney function? In fact, BUN is only an indicator of the metabolism of nitrogenous substances in the body. The result of BUN measurement alone is not enough to confirm any disease diagnosis.
Under normal kidney function, these small molecules are filtered out from the glomerulus, so it can be used as a diagnostic and screening indicator of glomerular filtration function. When glomerular filtration is reduced, blood creatinine and urea nitrogen are increased due to retention.
The etiology of high urea nitrogen may be organic renal impairment.
1, chronic renal failure due to various primary glomerulonephritis, pyelonephritis, interstitial nephritis, renal tumor, polycystic kidney, etc.
2, acute renal failure when renal function is mildly impaired, urea nitrogen can be unchanged, but the glomerular filtration rate drops to less than 50% before urea nitrogen can rise.
In addition, in the case of dehydration or other causes of insufficient effective blood volume in the body, it can cause a transient increase in BUN due to reduced renal blood flow. Sometimes a similar phenomenon can occur after a high protein diet. Therefore, there is no need to be nervous when the blood BUN is elevated, but a thorough examination is necessary to clarify the cause.
Blood urea nitrogen (BUN) measurement is a method to detect the level of urea nitrogen in standardized blood samples. According to the American Association for Clinical Chemistry (AACC), the BUN assay is primarily used to assess kidney health. Recently, Dr. Jennifer Huizen published an article on the MNT website detailing the reasons, timing, precautions, and interpretation of results for the BUN assay, organized as follows.
Reasons and timing of BUN measurement
BUN measurements are performed clinically for a variety of reasons, primarily to check or monitor kidney and liver function.
Since urea nitrogen is a breakdown product of protein, blood urea nitrogen levels are highly susceptible to liver and kidney effects. BUN measurement is often required in patients suspected of having kidney or liver disease. According to the Centers for Disease Control and Prevention (CDC), 10 percent of adults in the United States have long-term kidney disease, and most are unaware of it.
Symptoms of kidney disease
1.Frequent urination, especially at night
2.Changes in urine volume
3, Burning sensation in the urethra during urination
4.Frothy urine, coffee-colored or bloody urine
5.Diarrhea
6.Joint or bone pain, especially around the kidneys
7.Muscle spasm
8, restless legs during sleep
9.Sleep disorder
10.Fatigue
11.Lack of concentration
12.Itching
13.Loss of appetite
14, Swelling or puffiness, especially in the face, wrists, ankles, abdomen and thighs
15.High blood pressure
Liver disease symptoms
1.Dark urine
2.Pale face, blood in stool or tarry stool
3.Yellowing of skin or sclera
4.Easy bruising
5.Loss of appetite
6.Nausea or vomiting
7.Weight loss
8.Lack of energy or weakness
9.Stomach pain and edema
10.Oedema of lower limbs and ankles
11.Itching
Precautions before BUN measurement
The National Institute of Diabetes and Digestive and Kidney Diseases explains that most medications can affect BUN levels and kidney function. Over-the-counter painkillers, especially NSAIDS, can affect kidney function, such as ibuprofen, naproxen and aspirin. Natural diuretics, such as caffeine and steroids, can also affect kidney function. Antibiotics can also affect BUN levels.
Commonly prescribed drugs that can affect the kidneys causing abnormal BUN levels are
1.Amphotericin B
2. Carbamazepine
3.Celecoxib
4.Cephalosporin
5.Tachyphylaxis
6.Methotrexate
7.Methyldopa
8.Penicillin
9.Rifampicin
10.Antiseptic
11.Sulfonamides
12.Tetracycline
13.Thiazide diuretics
14.Vancomycin
The National Kidney Foundation believes that dietary supplements can also negatively affect the kidneys, leading to abnormal BUN levels. In general, natural health products are not regulated by the FDA. This means that there is no strong evidence on the effective dose, source, and precise mix of dietary supplements. It also means that herbal supplements may contain nephrotoxic ingredients, such as heavy metals or chemicals similar to aristolochic acid. Patients with kidney disease are generally advised to avoid natural supplements and to control phosphorus and potassium intake.
Interpretation of BUN measurement results
Normal blood urea nitrogen level is 7-22 mg/dl; blood urea nitrogen > 50 mg/dl indicates the possible presence of some disease.
The causes of elevated BUN level are.
1.Kidney injury, kidney failure or kidney disease
2.Dehydration
3.Shock
4.Urinary tract obstruction or disease
5.Gastrointestinal disease or bleeding
6.Heart disease
7.Heart failure
8.Excessive protein intake
9, poor blood circulation
10.Obesity
11.Hypercholesterolemia
The causes of lower BUN level are
1.Liver failure
2.Water toxicity
3.Insufficient protein intake
4.Malnutrition
BUN level is also affected by age, gender, and pregnancy. Usually, BUN level increases with age.
BUN levels of different ages and genders
Children: 5-18 mg/dl
Adult male: 8-20 mg/dl
Adult females: 6-20 mg/dl
BUN measurement also helps to determine the efficacy of renal therapies such as dialysis.
Follow-up treatment and testing
A BUN measurement alone is not sufficient to confirm a diagnosis of any disease. If the BUN result is abnormal, the clinician usually needs to perform additional tests. Creatinine tests and kidney tests can help diagnose kidney and liver disease. Some patients also need potassium, sodium and calcium levels, urinalysis and a blood urea nitrogen/creatinine ratio (normal values are 10:1-20:1).
Patients with abnormal BUN levels are treated differently depending on the cause and severity of the disease. Those with organ failure usually require intensive therapy and dialysis, while those with small changes in BUN levels may only require long-term monitoring.
Those with abnormal BUN levels due to excessive protein intake may limit the intake of protein-rich foods such as meat, fish, legumes and dairy products, and increase the intake of fruits and vegetables. Maintaining hydration status can also help prevent an increase in BUN.
BUN levels are also associated with hypertension and diabetes. Since stress has a greater impact on blood pressure, exercising and relieving stress may help stabilize BUN levels. Controlling blood sugar levels can also help maintain normal BUN levels.