Overview.
The Basic Metabolic Panel is a streamlined 8-test panel that focuses on your body's most essential chemical functions: blood sugar, kidney function, and electrolyte balance. It's often the go-to test for urgent evaluations, medication monitoring, and when liver function isn't a primary concern.
The BMP measures glucose, calcium, and electrolytes (sodium, potassium, chloride, CO2/bicarbonate), plus kidney function markers (BUN and creatinine). It provides essential information for managing diabetes, kidney disease, and electrolyte disorders without the liver tests included in a CMP.
What's included.
- Glucose — normal: 70-99 mg/dL · Blood sugar level
- Creatinine — normal: 0.7-1.3 mg/dL · Kidney filtration function
- BUN — normal: 7-20 mg/dL · Kidney function and hydration
- Sodium — normal: 136-145 mEq/L · Fluid balance and nerve function
- Potassium — normal: 3.5-5.0 mEq/L · Heart and muscle function
- Chloride — normal: 98-106 mEq/L · Acid-base balance
- CO2 (Bicarbonate) — normal: 23-29 mEq/L · Acid-base status
- Calcium — normal: 8.5-10.5 mg/dL · Bone and nerve function
Preparation.
Fasting required — 8 hours.
When: Can be drawn any time but fasting morning draws are optimal. Results typically available same day or within 24 hours.
- Fast for 8-12 hours for accurate glucose
- Water is allowed and encouraged
- Continue prescribed medications unless told otherwise
- Note if you've had recent diarrhea or vomiting (affects electrolytes)
When it's ordered.
- Emergency department evaluations
- Monitoring diuretics or blood pressure medications
- Managing diabetes (glucose and kidney function)
- Evaluating dehydration or fluid balance
- Pre-procedural assessment
- Quick metabolic status check
- When liver function isn't a concern
Interpretation.
What normal means
Your kidneys are filtering waste effectively, blood sugar is controlled, and electrolytes are balanced. Essential metabolic functions are working properly.
Abnormal patterns
High potassium (>5.0 mEq/L)
Possible causes
- Kidney dysfunction
- ACE inhibitors or potassium-sparing diuretics
- Hemolysis (blood sample issue)
- Acidosis
Next steps
- Repeat to rule out sample hemolysis
- EKG if significantly elevated
- Review medications
- Check kidney function
Low sodium (<136 mEq/L)
Possible causes
- Overhydration
- SIADH
- Diuretics
- Adrenal insufficiency
- Heart failure
Next steps
- Assess fluid intake and output
- Check urine sodium and osmolality
- Review medications
High BUN with normal creatinine
Possible causes
- Dehydration
- High protein diet
- GI bleeding
- Catabolic state
Next steps
- Hydrate and repeat
- Assess protein intake
- Check for GI symptoms
Cost & access.
Very affordable; typically $10-30 without insurance. Covered by most insurance as routine or diagnostic testing. Often used when a full CMP isn't necessary.
FAQs.
When should I choose a BMP instead of a CMP?
Choose a BMP when you only need to check kidney function, glucose, and electrolytes—for example, monitoring blood pressure medications or managing diabetes. Choose a CMP when you also want to assess liver health.
Can a BMP detect diabetes?
A BMP can show elevated glucose suggesting diabetes, but a formal diagnosis requires either HbA1c, fasting glucose on two occasions, or an oral glucose tolerance test.
Why are electrolytes important?
Electrolytes like sodium and potassium regulate fluid balance, muscle contraction, nerve function, and heart rhythm. Imbalances can cause symptoms ranging from fatigue to dangerous heart arrhythmias.