Comprehensive Metabolic Panel (CMP)
Also known as: Chem-14, Chemistry panel
The CMP is a 14-test panel covering glucose, electrolytes, kidney function, and liver enzymes in a single draw. Most adults have at least one CMP a year as part of routine check-ups.
Venous blood (serum separator tube)
4–6 hours
Required
Metabolic Panel
8–12 hours fasting gives the most accurate glucose and liver enzyme readings.
Reference Ranges
| Measurement | Reference Range | Unit |
|---|---|---|
| Glucose (fasting) | 70 – 99 | mg/dL |
| BUN | 7 – 25 | mg/dL |
| Creatinine (men) | 0.74 – 1.35 | mg/dL |
| Creatinine (women) | 0.59 – 1.04 | mg/dL |
| Sodium | 136 – 145 | mmol/L |
| Potassium | 3.5 – 5.1 | mmol/L |
| Calcium | 8.6 – 10.3 | mg/dL |
| ALT | 7 – 56 | U/L |
| AST | 10 – 40 | U/L |
| Albumin | 3.4 – 5.4 | g/dL |
| Total protein | 6.3 – 8.2 | g/dL |
Reference ranges are typical adult values. Your laboratory may use slightly different intervals — always use your lab's reported reference.
What This Test Measures
The CMP groups four categories of tests: (1) blood sugar (glucose), (2) electrolytes and fluid balance (sodium, potassium, carbon dioxide, chloride), (3) kidney function (BUN, creatinine), and (4) liver health (ALT, AST, ALP, bilirubin, albumin, total protein). Together they give a snapshot of how major organ systems are performing.
When Is This Test Ordered?
- Annual wellness screening
- Monitoring patients on medications that affect the kidneys or liver
- Evaluating hypertension, diabetes, or liver disease
- Pre-operative risk assessment
- Fatigue, weight loss, or oedema workup
When Results Are High
High glucose signals diabetes or pre-diabetes. Elevated creatinine or BUN points to reduced kidney filtration. Raised ALT/AST indicates liver cell damage. High potassium (hyperkalaemia) is a cardiac emergency above 6.5 mmol/L.
When Results Are Low
Low sodium (hyponatraemia) causes neurological symptoms if it falls below 125 mmol/L. Low albumin reflects poor nutrition or liver disease. Low glucose (hypoglycaemia) can cause confusion and seizures below 55 mg/dL.
Reading the kidney section: BUN, creatinine, and eGFR
BUN (blood urea nitrogen) and creatinine are waste products filtered by the kidneys. When filtration drops, both rise. The BUN:creatinine ratio helps differentiate causes: a ratio above 20 suggests dehydration or gastrointestinal bleeding; a ratio below 10 suggests liver disease or malnutrition.
eGFR (estimated glomerular filtration rate) is not always printed on older panels but can be calculated automatically. Values above 90 are normal; 60–89 is mildly reduced; below 60 for three months meets criteria for chronic kidney disease.
ALT vs AST: liver enzymes decoded
| Enzyme | Location | Best at detecting |
|---|---|---|
| ALT (alanine aminotransferase) | Mainly liver | Hepatitis, fatty liver, medication damage |
| AST (aspartate aminotransferase) | Liver, heart, muscle | Liver disease, heart attack, muscle damage |
| ALP (alkaline phosphatase) | Liver, bile ducts, bone | Bile duct obstruction, bone disease |
Factors That Can Affect Your Result
- Eating within 8 hours artificially raises glucose and may affect liver enzymes
- Strenuous exercise raises creatinine and AST temporarily
- Dehydration concentrates all values
- Haemolysis (ruptured RBCs in the tube) falsely elevates potassium and AST
Tracking This Test Over Time
Your eGFR — estimated from creatinine, age, and sex — is one of the most valuable long-term trends. A 25% drop over two years signals declining kidney function even when both values stay 'normal'.
Track your CMP in LoomsRelated Tests
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Medical disclaimer
This page is for educational purposes only and does not constitute medical advice. Reference ranges vary between laboratories, and results must be interpreted in the context of your symptoms, history, and other tests. Always discuss your results with your healthcare provider. Content reviewed by the Looms medical team, 2026-06-01.