Urea

Also known as: Blood Urea, BUN (Blood Urea Nitrogen)

Kidney Blood
Patient Friendly Summary

Urea is a supporting actor to creatinine. Doctors read them together — urea high but creatinine normal often points to dehydration rather than kidney damage.

What this test means

Urea is formed when the body breaks down protein and is cleared by the kidneys. It rises with reduced kidney function but also with dehydration and high-protein intake.

Why it is done

It is done together with creatinine to assess kidney function and hydration status.

Understanding your value

If your value is high

High urea can be seen with dehydration, reduced kidney function, bleeding in the gut, or high protein breakdown.

If your value is low

Low urea can be seen with low protein intake or liver conditions and is usually less concerning.

About the normal range

Common ranges are roughly 15–40 mg/dL for urea (labs reporting BUN use different numbers). Urea moves more with hydration than creatinine does.

When to consult a doctor

Discuss raised urea with your doctor, particularly alongside raised creatinine, swelling, or decreased urination.

Frequently Asked Questions

It is done together with creatinine to assess kidney function and hydration status. Your doctor will decide if this test is right for your situation.

High urea can be seen with dehydration, reduced kidney function, bleeding in the gut, or high protein breakdown. This needs clinical correlation — always discuss your report with your doctor.

Low urea can be seen with low protein intake or liver conditions and is usually less concerning. This needs clinical correlation — always discuss your report with your doctor.

A single value rarely tells the whole story. Results need to be read together with your symptoms, history, and other tests. Please consult your doctor for a proper interpretation.

Quick Facts

  • TestUrea
  • Short formsBlood Urea, BUN (Blood Urea Nitrogen)
  • Sample typeBlood
  • CategoryKidney

Related Terms

Kidney Function High

Specialists

Nephrology General Medicine

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Disclaimer: This information is for patient education only and does not replace medical advice, diagnosis, or treatment. Always consult a qualified doctor.