Basic Metabolic Panel (BMP) vs Comprehensive Metabolic Panel (CMP)
A CMP includes all 8 components of a BMP plus 6 additional liver function tests, making it a 14-component panel that provides both metabolic and hepatic assessment. 1
BMP Components (8 tests)
The Basic Metabolic Panel measures kidney function, electrolytes, and glucose 1:
- Electrolytes: Sodium, potassium, chloride, and carbon dioxide (bicarbonate) 1
- Kidney function: Blood urea nitrogen (BUN) and creatinine 1
- Glucose: Fasting blood glucose 1
- Calcium: Total calcium 1
CMP Components (14 tests)
The Comprehensive Metabolic Panel includes all BMP components plus liver function tests 1:
- All 8 BMP components (listed above) 1
- Liver function tests: Alanine aminotransferase (ALT), aspartate aminotransferase (AST), alkaline phosphatase (ALP), total bilirubin, total protein, and albumin 2
When to Order Each Panel
Order a BMP when you need basic metabolic assessment without liver evaluation 2:
- Routine electrolyte monitoring 1
- Kidney function assessment 1
- Glucose monitoring in diabetes 1
- Patients with no clinical indicators of liver disease 2
Order a CMP when comprehensive metabolic assessment including liver function is needed 1:
- Right upper quadrant pain 2
- Drug overdose 2
- Known liver disorder 2
- Malignancy 2
- Heart disease 2
- Jaundice 2
- Hepatomegaly 2
- Ascites or peripheral edema 2
- Initial cancer workup (renal cell carcinoma, myeloproliferative neoplasms) 3
- Obesity assessment requiring liver function evaluation 1
- Acute stroke evaluation 3
- NAFLD screening in high-risk patients 3
Clinical Pitfalls
Avoid ordering a CMP when liver assessment is not clinically indicated 2:
- Patients without any of the 12 clinical variables associated with abnormal liver function have a 16% false-negative rate, but these are typically marginally abnormal values requiring no intervention 2
- Unnecessary CMP testing instead of BMP can waste approximately $21 per test without changing clinical outcomes 2
- Panel-based ordering has increased total calcium testing by more than 3-fold without changing the rate of calcium-related diagnoses 4
The CMP does NOT include a lipid panel 1: