BUN/Creatinine Ratio Panel
Pairs two kidney markers to help tell apart causes of rising waste products in the blood.
Consider this test if:
- Investigating a high BUN or creatinine flagged on a recent metabolic panel
- Symptoms of dehydration, swelling, or fluid overload alongside kidney concerns
- Tracking kidney function with heart failure, high blood pressure, or diabetes
- Wanting a baseline of how well your kidneys are filtering
- HSA/FSA eligible
- Results delivered to your dashboard · Reviewed by a real clinician
- Drawn at a CLIA/CAP-accredited lab near you ·
Pre-test considerations
Stay well hydrated, since dehydration raises BUN and the ratio. A very high-protein meal or heavy creatine supplementation before the draw can also push values up; keep intake consistent if you are comparing results over time. Fasting is not required for this panel.
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What this test is for
This panel measures urea nitrogen (BUN), creatinine, the ratio between them, and eGFR, an estimate of how well your kidneys filter blood. The BUN/creatinine ratio is most useful for sorting out why those waste products are elevated: a high ratio points toward reduced blood flow to the kidneys (such as dehydration or heart failure), urinary obstruction, or extra urea from gastrointestinal bleeding or a high-protein load, while a low ratio can reflect liver disease or low protein intake. In most chronic kidney disease the ratio stays relatively normal, which is why eGFR and creatinine carry more weight for tracking long-term filtration. BUN also shifts quickly with hydration and protein intake, so this panel reads best alongside your symptoms and a recent baseline. The broader Kidney Panel adds a urine albumin-to-creatinine ratio, the earliest sign of kidney damage, if your goal is screening rather than working out the cause of an abnormal reading.
Biomarkers tested
Includes 4 biomarkers
This ratio compares urea nitrogen, a waste product the liver makes from protein breakdown, to creatinine, a byproduct of muscle metabolism, giving context that either marker alone can't. A high ratio points toward dehydration, high protein intake, or reduced blood flow to the kidneys, while a low ratio suggests liver trouble or a low-protein diet, so it's most useful for interpreting an abnormal BUN or creatinine rather than standing alone. Order it alongside kidney function testing when you're investigating fatigue, unexplained swelling, or changes in urination, or when you want to rule out dehydration as the cause of an odd creatinine result.
- Specimen
- Serum or plasma
- Measures
- Ratio
Creatinine is a waste product released as your muscles break down creatine for energy, and your kidneys filter it out of the blood at a steady rate. When creatinine rises, it usually means the kidneys are filtering less efficiently, making it the core marker for kidney function and the basis for calculating eGFR. Test it as a baseline for kidney health, to monitor the impact of blood pressure, diabetes, high-protein diets, or supplements like creatine, or to investigate unexplained fatigue, swelling, or changes in urination.
- Specimen
- Serum or plasma
- Measures
- Mass concentration
- Specimen
- Serum, plasma, or blood
- Method
- Creatinine-based (CKD-EPI)
- Measures
- Ratio
Blood urea nitrogen tracks the waste product your liver makes when it breaks down protein, cleared by kidneys that filter it out of circulation. High BUN points to reduced kidney filtration, dehydration, or a high protein intake, while low levels can reflect liver trouble or very low protein diets. Paired with creatinine, it rounds out a kidney function baseline and helps investigate fatigue, swelling, changes in urination, or unexplained shifts tied to diet, hydration, or medication changes.
- Specimen
- Serum or plasma
- Measures
- Mass concentration
What to expect
- 1 Book instantly
Click, book, done. Choose a convenient lab location near you. Transparent, up-front pricing.
- 2 Quick lab visit
Testing to fit your busy schedule, usually 15 minutes or less. Walk-in and appointments available.
- 3 Fast, dashboard-delivered results
Your results post straight to your dashboard as soon as the lab completes them.
- 4 Expert guidance
Included with Mito membership. A clinician reviews your results and your personalized action plan follows, with clear next steps.
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Frequently asked questions
View all FAQsHow does pricing work?
Every test shows the member price next to the standard non-member price, so you can see what membership saves you. The member price is our cost — covering the lab and what it takes to run the service — never a profit on the test itself; Mito makes its money on the $9 membership, not on marking up your tests. Membership is $9/mo, and you still pay the lab’s order fee. Prices are itemized before you pay, with no hidden fees.
Where do I get tested?
Choose a partner lab (Quest, Labcorp, or BioReference) at checkout. If your cart spans multiple tests, we consolidate the whole order onto a single lab so you only make one visit.
Is this eligible for HSA/FSA?
Yes. This test is HSA/FSA eligible, and you can pay with your HSA/FSA card at checkout.
When will I get my results?
Your results post to your dashboard once your lab completes them, then a clinician reviews them and your full analysis and personalized action plan (with clear next steps) follow. Turnaround varies by test: specialty assays and at-home kits take longer, and each test shows its expected turnaround before you buy.
Do I need a doctor’s order?
No. Mito provides the lab order for you, so you can book and get tested without a separate doctor visit.
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