Description of the Analysis:

BUN (Blood Urea Nitrogen) is a laboratory test that measures the amount of urea nitrogen in your blood. Urea is a waste product created in the liver during the breakdown of proteins. Under normal conditions, the kidneys filter urea from the blood and excrete it through urine. Because this process is continuous, the level of BUN in the blood serves as a key indicator of how effectively your kidneys and liver are functioning.

What Does the Analysis Represent?

• Goal: To evaluate kidney function and check how well the organs are clearing metabolic waste from the blood.
• Main Application: Diagnosing renal failure, monitoring patients with chronic conditions (such as diabetes or hypertension), assessing dehydration levels, and checking the effectiveness of dialysis.
• Biological Process: The analysis reflects the balance between urea production in the liver and its excretion by the kidneys.

Recommendations for the Test (General)

• Fasting: Mandatory. You must fast for 8–12 hours before the blood draw. Only plain, non-carbonated water is allowed.
• Diet: Avoid excessive protein intake (meat, fish, cheese) for 24 hours before the test, as this can temporarily spike urea levels.
• Timing: Morning collection is preferred to obtain a stable baseline result.
• Material: Venous blood (serum).

What Can Affect the Results?

• High-Protein Diet: A diet very high in protein directly increases BUN levels.
• Hydration Status: Dehydration (due to insufficient fluid intake, vomiting, or diarrhea) leads to a higher concentration of urea nitrogen.
• Medications: Certain drugs, such as corticosteroids, tetracyclines, and diuretics, can elevate the readings.
• Age and Gender: BUN levels naturally increase with age; men typically have slightly higher levels due to greater muscle mass.
• Pregnancy: BUN levels often decrease during the second and third trimesters.

When to Take the Test?

• Symptoms of Kidney Dysfunction: Appearance of edema (swelling, especially around the ankles and eyes), changes in urine color or frequency, persistent fatigue, or pain in the kidney area.
• Monitoring Conditions: Presence of diabetes, high blood pressure, or cardiovascular diseases that increase the risk of kidney damage.
• Acute States: Suspected severe dehydration, gastrointestinal bleeding, or intoxication.

How to Interpret the Results?

Important: BUN levels must be evaluated by a physician in the context of your hydration and kidney function. High BUN: Often indicates that the kidneys aren’t filtering waste effectively, but can also be caused by high protein intake or dehydration. Low BUN: May be seen in cases of severe liver disease or overhydration.

Possible Further Investigations

• Creatinine Blood Test: To calculate the estimated Glomerular Filtration Rate (eGFR).
• Albumin-to-Creatinine Ratio (ACR): A urine test to detect early signs of kidney damage.
• Electrolyte Panel: To evaluate levels of sodium, potassium, and calcium.
• Ultrasound of the Kidneys: To visualize structure and rule out urinary tract obstructions.

When Does the Next Step Make Sense? 

The next step is necessary if BUN levels are outside the reference range, especially if accompanied by an elevated creatinine level. Since BUN is sensitive to diet and hydration, a physician may order a repeat test after adjusting fluid intake. Timely diagnosis helps prevent acute conditions from progressing into chronic kidney disease.

👉 If necessary, you can discuss the results of the analysis with a specialist, such as a Nephrologist (Doctors – TAMC), Urologist (Doctors – TAMC)