Guide Updated Oct 6, 2026

Basic Metabolic Panel (BMP): 8 Tests and Results Explained

A basic metabolic panel (BMP) measures eight substances: glucose, calcium, sodium, potassium, chloride, carbon dioxide (CO2), blood urea nitrogen (BUN) and creatinine. Read the eight rows as a group, distinguish extra calculated results, and check what an abnormal flag means for your report.

If the lab or clinician says a result is critical, follow their urgent instructions. An ordinary H or L flag and a critical-result alert are different; this guide and an uploaded-report explanation cannot determine whether it is safe to wait.

The BMP at a glance

  • Eight measured tests: glucose, calcium, sodium, potassium, chloride, CO2, BUN and creatinine.
  • BMP versus CMP: the CMP adds albumin, total protein, ALP, ALT, AST and bilirubin, for 14 tests in total.
  • CO2 mainly reflects bicarbonate in the chemistry panel; it is not a pulse-oximeter oxygen reading.
  • A flag is not a diagnosis. Read the lab’s range, sampling conditions, related results and previous reports.
  • Fasting may be required. Check the order rather than assuming every BMP has the same preparation.

A BMP helps assess blood sugar, kidney function, fluid and electrolyte balance, and acid–base balance. To read your report, first identify the eight measured tests, then pair each result with its unit and the lab’s range. The worked example below shows how to review one flagged row without treating the whole panel as a single pass-or-fail result.

What are the eight tests in a basic metabolic panel?

The standard BMP combines glucose and calcium with four electrolyte-related measurements and two kidney-related waste products. MedlinePlus lists the following eight tests.

Jump to example ranges, a sample report, high and low results, extra rows or questions after an abnormal result.

BMP test / common label What it measures Common reporting units
Glucose Blood sugar at the time of the draw mg/dL or mmol/L
Calcium / Ca Total calcium in the sample mg/dL or mmol/L
Sodium / Na An electrolyte involved in fluid balance mmol/L or mEq/L
Potassium / K An electrolyte needed by nerves, muscles and the heart mmol/L or mEq/L
Chloride / Cl An electrolyte read with sodium and acid–base markers mmol/L or mEq/L
CO2 / total CO2 / bicarbonate Mostly bicarbonate, involved in acid–base balance mmol/L or mEq/L
BUN / blood urea nitrogen Nitrogen in urea, a waste product mg/dL; some reports instead show urea in mmol/L
Creatinine / Cr A waste product used to help assess kidney filtration mg/dL or µmol/L

What are normal BMP reference ranges?

There is no single range table that overrides your own report. The examples below come from the MedlinePlus BMP encyclopedia. Laboratories, methods and patient groups differ, especially for creatinine. These are example reference intervals, not critical-value thresholds or treatment targets.

Test Example reference interval
Glucose 64–100 mg/dL (3.55–5.55 mmol/L)
Calcium 8.5–10.2 mg/dL (2.13–2.55 mmol/L)
Sodium 136–144 mmol/L
Potassium 3.7–5.2 mmol/L
Chloride 96–106 mmol/L
CO2 23–29 mmol/L
BUN 6–20 mg/dL
Creatinine 0.8–1.2 mg/dL (70.72–106.08 µmol/L)
A lab can use a different valid reference interval. Glucose interpretation also depends on fasting or random sampling; a laboratory interval is not interchangeable with a diagnostic cutoff. See how reference ranges work.

What is the difference between a BMP and a CMP?

A BMP has eight tests. A comprehensive metabolic panel (CMP) contains the same eight plus albumin, total protein, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST) and bilirubin. The CMP therefore has 14 measured tests. MedlinePlus’s CMP overview describes those added proteins and enzymes.

Question BMP CMP
Standard measured tests 8 14
Glucose, calcium, electrolytes, BUN and creatinine Included Included
Albumin and total protein Not part of the standard BMP Included
ALP, ALT, AST and bilirubin Not part of the standard BMP Included
Complete blood count or cholesterol panel Separate tests Separate tests
Fasting May be requested May be requested

The ordering clinician chooses the measurements needed. If your report also lists liver enzymes or protein tests, use the CMP report guide for those additional rows. A BMP does not measure cholesterol, blood cell counts or HbA1c; those require separate tests.

How do you read a BMP result row by row?

The fictional report below uses illustrative lab ranges. Start with the result, unit and range in the same row. Then check the fasting note and any collection comments before treating a flag as a change in health.

Test Example result This example lab’s range Flag
Glucose 108 mg/dL 70–99 mg/dL H
Calcium 9.4 mg/dL 8.6–10.2 mg/dL —
Sodium 140 mmol/L 135–145 mmol/L —
Potassium 4.3 mmol/L 3.5–5.1 mmol/L —
Chloride 103 mmol/L 98–107 mmol/L —
CO2 25 mmol/L 22–29 mmol/L —
BUN 15 mg/dL 7–20 mg/dL —
Creatinine 0.9 mg/dL 0.6–1.2 mg/dL —

Glucose is the only flagged row in this example. It is 108 mg/dL, compared with this fictional lab’s 70–99 mg/dL interval. Before interpreting that difference, check whether the specimen was fasting or random. The seven unflagged rows do not cancel the glucose result, and the H flag alone does not establish diabetes.

A useful question for the ordering clinician is: “My glucose was 108 mg/dL and the other seven BMP results were within range. Does the fasting status change how you interpret that result, and is any follow-up needed?” For glucose-specific interpretation and separately ordered HbA1c results, see the diabetes panel guide.

The different ranges in the two tables are deliberate: one is a published reference example, the other belongs to a fictional report. Keep a result paired with the range from its own lab. See how to read flagged values.

For an overview of what to check when a row is outside its range, see high and low results across the eight BMP markers.

What does CO2 mean on a BMP?

CO2 on a BMP means total carbon dioxide content, most of which is present as bicarbonate (HCO3). Bicarbonate helps buffer acids in the blood. The MedlinePlus CO2 guide lists labels such as total CO2, TCO2, bicarb and HCO3.

A chemistry-panel CO2 result is different from oxygen saturation and from the partial pressure of CO2 measured on a blood gas. A high or low CO2 result needs the other electrolytes and the testing context; the single row does not identify the cause.

Why does my BMP report show more than eight results?

Eight refers to the substances measured by a standard BMP, not necessarily the number of lines printed on the report. Laboratories may display calculations beside those measurements or add separately ordered tests.

For example, eGFR estimates filtration using blood test results and patient information. An anion gap is calculated from electrolytes. Neither is a ninth substance measured by the BMP.

Extra result sometimes shown How it relates to the BMP
eGFR An estimate of kidney filtration, often calculated using creatinine and patient information; not a ninth measured BMP substance.
BUN/creatinine ratio A calculation from two BMP values; retain the units and lab explanation.
Anion gap A calculation using electrolytes; some labs include potassium and others do not.
Urea Related to BUN but not the same numerical measurement. Do not compare a urea number directly with BUN.

If your report includes albumin, total protein, magnesium or phosphorus, check the panel name and any additional orders. Those are not part of the standard eight-test BMP. The kidney panel guide covers renal reports and the relationship between creatinine and eGFR.

What can high or low BMP results mean together?

First check whether the report uses an ordinary H/L flag or a critical alert. Then review the affected marker alongside related results. Glucose requires its sampling context; BUN and creatinine are read together; sodium, potassium, chloride and CO2 describe related parts of fluid and electrolyte balance.

Use this eight-row overview to orient yourself within the panel. Each possibility is a clue, not a diagnosis. The linked marker pages explain individual causes and follow-up tests in detail.

BMP marker If flagged high If flagged low Read alongside
Glucose More circulating glucose; recent food and glucose regulation both matter. Less circulating glucose; fasting duration and glucose-lowering medicines matter. The fasting/random note and HbA1c if separately ordered.
Calcium May involve calcium regulation; total calcium includes protein-bound calcium. May reflect low blood proteins as well as low calcium. Albumin or ionized calcium if available; neither is part of a standard BMP.
Sodium Can reflect too little water relative to sodium. Can reflect too much water relative to sodium; high glucose may also affect the reading. Glucose, chloride and the fluid/medication history.
Potassium May involve kidney handling, medicines or a sample-related elevation. May involve potassium loss or medicine effects. Creatinine/eGFR, CO2 and any hemolysis comment. Both directions can matter for heart function.
Chloride May accompany a fluid-balance or acid–base change. May also reflect a fluid-balance or acid–base change; the direction alone does not identify which. Sodium, CO2 and the anion gap if reported.
CO2 / bicarbonate May accompany an alkalosis pattern or compensation for a breathing-related change. May accompany an acidosis pattern or a different breathing-related change. Chloride and the anion gap; a blood gas may be needed to distinguish the acid–base pattern.
BUN Can reflect reduced clearance or increased urea production/concentration. Can reflect lower protein intake or reduced urea production. Creatinine/eGFR and the diet/fluid history; an isolated BUN flag is not a filtration diagnosis.
Creatinine May reflect reduced filtration, but muscle, diet and medicines can also affect the number. Often reflects lower muscle mass; a lower value is not automatically better kidney function. eGFR, BUN and previous creatinine results in the same units.

For example, BUN above range with creatinine inside range raises a different question from both values rising together. Chloride is more informative when you also look at CO2 and any reported anion gap. An ordinary H/L table cannot replace the response to a critical-result call.

The overview draws on MedlinePlus’s individual glucose, calcium, sodium and chloride guidance, together with the potassium, CO2, BUN and creatinine references listed below.

A specimen comment can matter. For example, MedlinePlus’s potassium guidance notes that blood cells breaking during collection can affect a potassium result. That possibility is for the clinician or lab to assess; do not dismiss a high potassium as a collection error yourself.

A critical-result call takes priority over reading or uploading the report. Follow the lab or clinician’s instructions. For an ordinary flag, see the difference between a flag and a critical result.

Do you need to fast before a basic metabolic panel?

You may be asked to fast before a BMP, often for eight hours. The glucose measurement and the purpose of the order affect the instructions. Do not assume that an urgent or random panel should be delayed for fasting; confirm the preparation with the ordering team.

When fasting is requested, plain water is usually allowed and coffee should wait. Ask about medicines and supplements rather than stopping them yourself. The fasting guide gives a timing table and explains what to do if you ate.

What should you ask after an abnormal BMP result?

Bring the whole BMP report to the ordering team, including the draw date, fasting note, units, reference intervals and any specimen comments. Start with the flagged row and the companion results identified in the table above.

What you noticed on this BMP A question to take to the clinician or lab
Only glucose is flagged Was this a fasting or random specimen, and does the collection context change the interpretation?
BUN or creatinine is flagged How do the two results, any reported eGFR and my previous kidney results fit together?
Potassium is flagged and the report mentions hemolysis Does the specimen comment affect this result, and what follow-up do you want? Do not assume the flag is only a collection error.
A result changed since the last BMP Are the units, lab intervals and collection conditions comparable, and is the change meaningful in my case?
The lab called the result critical What immediate action should I take? Follow the urgent instructions already given.

For the general method of matching units and reference intervals, use comparing results from different labs. For repeated measurements, use tracking lab trends. Those guides cover the comparison process beyond this BMP example.

What changed in this guide?

October 6, 2026: added the eight-test table, sourced example ranges, a fictional full BMP and an overview of high/low flags; clarified calculated rows, CO2 labels and preparation. Focused the guide on the standard eight-test BMP and added questions to take to the ordering clinician after an abnormal result.

Eight tests, one panel

Your BMP results, explained together.

Upload your report. Read the glucose, electrolytes and kidney markers with plain-language explanations, each beside your lab's own reference range.

Works with Quest, Labcorp, MyChart & PDFs

Basic metabolic panel

8 tests
Three rows from a fictional BMP report
Test Result Lab range
Glucose 108 mg/dL · H 70–99
Potassium 4.3 mmol/L 3.5–5.1
Creatinine 0.9 mg/dL 0.6–1.2

Fictional sample · each result keeps its lab’s own range

Questions about BMP blood test results

What does BMP stand for on a blood test?
BMP stands for basic metabolic panel. The standard panel measures glucose, calcium, sodium, potassium, chloride, CO2, BUN and creatinine.
What does a basic metabolic panel test for?
A BMP helps assess blood glucose, fluid and electrolyte balance, acid–base balance and kidney function. It measures substances that support that assessment rather than diagnosing one disease on its own.
What is the difference between a BMP and a CMP?
A CMP includes the eight BMP tests plus albumin, total protein, ALP, ALT, AST and bilirubin, for 14 measured tests. The added rows cover proteins and liver-related measurements.
Does a BMP include liver tests or cholesterol?
The standard BMP does not include ALT, AST, ALP, bilirubin or a cholesterol panel. Those liver-related tests are part of a CMP, while cholesterol is measured in a separate lipid panel.
What is CO2 on a basic metabolic panel?
CO2 usually means total carbon dioxide content, which mainly reflects bicarbonate in a chemistry panel. It helps assess acid–base balance and is different from oxygen saturation or a blood-gas CO2 pressure.
Is eGFR one of the eight BMP tests?
No. eGFR is an estimate often calculated using creatinine and patient information. A lab can display it beside the BMP without adding a ninth measured substance.
Why are there more than eight rows on my BMP report?
A lab may print eGFR, an anion gap or a BUN/creatinine ratio alongside the eight measured tests. These are calculated results. Additional measured tests may come from a different panel or a separate order; check the test names and panel label.
Does a high glucose result on a BMP mean diabetes?
A high flag alone does not establish diabetes. Interpretation depends on whether the draw was fasting or random, the measured level, symptoms and any follow-up testing.
Do I need to fast before a BMP?
Fasting may be requested, often for eight hours. Follow the instructions for your order and check with the lab if they are unclear. Do not delay an urgent test just to complete a fast.
Are BMP normal ranges the same at every lab?
No. Laboratories and patient groups can use different intervals. Compare your result with the range on its own report; an example range table is not a universal treatment or critical-value threshold.

Sources

Written by BloodSight Editorial Team · Last updated

Disclaimer

This content is for informational and educational purposes only. It is not intended as medical advice, diagnosis, or treatment recommendation. Reference ranges may vary by laboratory. Always discuss your results with a qualified healthcare professional.

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