What's in a Basic Metabolic Panel?

A basic metabolic panel (BMP) is one blood draw that measures eight things: glucose, calcium, four electrolytes (sodium, potassium, chloride, and carbon dioxide, mostly as bicarbonate), and two waste products, blood urea nitrogen (BUN) and creatinine. Together they give a quick picture of your fluid balance, your blood sugar, and how well your kidneys are working, which is why it’s one of the most common tests in a checkup or a hospital. Each result is read against the range your lab prints, and a pattern across several results usually says more than any one of them.

This article is general information, not medical advice.

The Eight Tests

Test	What it reflects
Glucose	Your blood sugar; a high value can be a sign of diabetes
Calcium	A mineral your nerves, muscles, and heart need, which also helps blood clot
Sodium	An electrolyte that helps control the amount of fluid in your body
Potassium	An electrolyte almost all inside your cells, which your heart, nerves, and muscles need to work properly
Chloride	An electrolyte that helps control fluid and acid-base balance
Carbon dioxide (bicarbonate)	A waste product of metabolism, mostly carried as bicarbonate; too much or too little can signal a problem with acid-base balance
Blood urea nitrogen (BUN)	A waste product of protein breakdown, cleared by the kidneys
Creatinine	A waste product made as your muscles work, cleared by the kidneys, and the basis of eGFR

MedlinePlus describes the electrolytes as charged minerals that control the amount of fluid in your body and its acid-base (pH) balance, and BUN and creatinine as wastes your kidneys remove, so abnormal values can point to kidney disease, breathing problems, or complications of diabetes, among other conditions.

Reading the Results

• Use your lab’s range. Each lab prints its own reference range, which covers 95% of healthy people, so a value just outside it is often not a sign of anything; see What the Reference Range on Your Lab Results Actually Means
• Read it as a whole. Results mean more together, with your medications and history. A high BUN, for example, can come from kidney disease, but also, MedlinePlus notes, from dehydration, a high-protein diet, or certain medicines, and BUN usually rises with age.
• Kidney function is the eGFR. Most labs report an estimated glomerular filtration rate calculated from creatinine with the panel; see What Is eGFR, and Why Do Creatinine and Cystatin C Give Different Results?
• Glucose depends on fasting. You may be asked to fast for 8 hours first. A fasting glucose can be read against the American Diabetes Association’s thresholds: under 100 mg/dL is normal, 100 to 125 mg/dL is prediabetes, and 126 mg/dL or more, confirmed by a second test, is diabetes. A glucose taken after eating can’t. See What Does Your HbA1c Mean?
• Potassium is easily thrown off. MedlinePlus notes that repeatedly clenching and relaxing your fist just before or during the draw can raise it temporarily and give an incorrect result.

The Comprehensive Panel

A comprehensive metabolic panel (CMP) measures 14 things: the BMP’s eight plus albumin and total protein, and four liver tests, alkaline phosphatase (ALP), alanine aminotransferase (ALT), aspartate aminotransferase (AST), and bilirubin. If your report says CMP, it includes everything here.

Following It in Kaizora

Each test is its own metric on Labs: Serum Sodium, Serum Potassium, Serum Chloride, Serum Total Carbon Dioxide, Blood Urea Nitrogen, Serum Creatinine, and Serum Total Calcium, each logged with its time, laboratory, and printed range, so a result outside it is flagged. Glucose is Fasting Plasma Glucose when you fasted for at least 8 hours, which is flagged by the ADA’s thresholds by default, and Plasma Glucose otherwise. A draw’s results share their time and laboratory, so a panel’s results line up with each other and with any other tests from the same blood, and each one’s chart shows how it has changed over years.

The Short Version

• A BMP measures glucose, calcium, sodium, potassium, chloride, bicarbonate, BUN, and creatinine.
• It checks fluid and acid-base balance, blood sugar, and kidney function in one draw.
• Read each result against your lab’s range, and the panel as a whole with your doctor.
• A CMP adds albumin, total protein, and four liver tests.

Sources

• MedlinePlus, Basic metabolic panel (BMP).
• MedlinePlus, Comprehensive metabolic panel (CMP).
• MedlinePlus, Potassium blood test, BUN (blood urea nitrogen), Carbon dioxide (CO2) in blood, and Creatinine test.
• American Diabetes Association Professional Practice Committee, “2. Diagnosis and classification of diabetes: Standards of Care in Diabetes—2025,” Diabetes Care 48, Supplement 1 (2025): S27–S49. doi:10.2337/dc25-S002