DoctorAIA comprehensive metabolic panel (CMP) is a blood test that measures 14 substances, including glucose, electrolytes and markers of kidney and liver health. Doctors use it as a broad check of the body's chemistry, to monitor some conditions and medicines, and to look into symptoms.
What the CMP measures
Conventional US units come first, with SI units in brackets where labs commonly report them. These are typical adult ranges. Your report will print its own.
| Marker | What it is | Typical adult range | If higher | If lower |
|---|---|---|---|---|
| Glucose (fasting) | Blood sugar | 70 to 99 mg/dL (3.9 to 5.5 mmol/L) | A recent meal, stress or steroid medicines can raise it. Fasting values of 100 to 125 mg/dL, or 126 mg/dL and above on repeat tests, are in the prediabetes and diabetes ranges. | Skipped meals, alcohol, or diabetes medicines. Values below 70 mg/dL (3.9 mmol/L) are considered low. |
| Calcium | A mineral for bones, nerves and muscles | 8.6 to 10.2 mg/dL (2.15 to 2.55 mmol/L) | Overactive parathyroid glands, too much vitamin D or calcium supplement, dehydration, and some cancers. | Low vitamin D, low albumin, kidney disease or parathyroid problems. |
| Sodium | An electrolyte that helps balance body water | 135 to 145 mmol/L | Usually too little water or fluid loss. | Excess body water, heart, kidney or liver disease, water pills (diuretics) and some other medicines. |
| Potassium | An electrolyte important for heart and muscle function | 3.6 to 5.2 mmol/L | Kidney disease and some blood pressure medicines. A sample damaged in transit can also read falsely high. | Vomiting, diarrhea, water pills or low intake. |
| Chloride | An electrolyte that moves with sodium | 96 to 106 mmol/L | Often follows sodium or reflects acid-base changes. | Often follows sodium, or occurs with vomiting. |
| Carbon dioxide (bicarbonate) | Helps keep blood acid-base balance | 23 to 29 mmol/L | Vomiting or some lung conditions. | Kidney disease, diarrhea, or an acid build-up in the blood. |
| Blood urea nitrogen (BUN) | A waste product cleared by the kidneys | 7 to 20 mg/dL (2.5 to 7.1 mmol/L urea) | Dehydration, reduced kidney function, a high-protein diet or bleeding in the gut. | Low protein intake, liver disease or extra body water. |
| Creatinine | A muscle waste product cleared by the kidneys | Men: 0.74 to 1.35 mg/dL (65 to 119 µmol/L). Women: 0.59 to 1.04 mg/dL (52 to 92 µmol/L) | Reduced kidney function or dehydration. Large muscle mass and creatine supplements can also raise it. | Low muscle mass, older age or pregnancy. |
| Albumin | The main blood protein, made by the liver | 3.5 to 5.0 g/dL (35 to 50 g/L) | Usually dehydration. | Liver disease, protein loss through the kidneys, poor nutrition or inflammation. |
| Total protein | Albumin plus other blood proteins | 6.0 to 8.3 g/dL (60 to 83 g/L) | Dehydration, long-term inflammation or some blood disorders. | Liver or kidney disease, poor nutrition or poor absorption of nutrients. |
| Alkaline phosphatase (ALP) | An enzyme in the liver, bile ducts and bone | 44 to 147 U/L | Liver or bile duct problems, bone conditions, pregnancy, or growth in teenagers. | Uncommon. May relate to poor nutrition, zinc deficiency or rare inherited conditions. |
| Alanine aminotransferase (ALT) | An enzyme found mainly in the liver | 4 to 36 U/L | Can be a sign of liver irritation, for example from fatty liver, hepatitis, alcohol or medicines. | Usually not significant. |
| Aspartate aminotransferase (AST) | An enzyme in the liver, muscle and heart | 8 to 33 U/L | Liver irritation, but also muscle injury or strenuous exercise. | Usually not significant. |
| Bilirubin (total) | A yellow pigment from red cell breakdown, cleared by the liver | 0.1 to 1.2 mg/dL (2 to 21 µmol/L) | Gilbert syndrome (common and harmless), red cells breaking down, or liver or bile duct problems. | Usually not significant. |
Some reports add an eGFR (estimated glomerular filtration rate). Labs calculate it from your creatinine, age and sex to estimate how well the kidneys filter blood. A value that stays below 60 mL/min/1.73 m² on tests repeated over about three months is one of the markers doctors use when assessing chronic kidney disease.
Why your lab's range may differ
Enzyme tests such as ALP, ALT and AST vary the most between labs because methods and reference groups differ, and some labs print different ranges for men and women. Electrolytes and creatinine also vary a little. Use the range on your own report, and remember that values slightly outside it are common in healthy people.
What can affect your results
- Fasting: glucose is usually measured after fasting for about 8 hours. A recent meal can raise it and change some other values.
- Hydration: dehydration can raise BUN, creatinine, sodium and protein values.
- Medicines and supplements: water pills, blood pressure medicines, steroids, acetaminophen in large amounts, creatine and others can shift results.
- Exercise: hard exercise in the day or two before can raise AST and creatinine.
- Alcohol and diet: alcohol can raise liver enzymes, and a high-protein meal can raise BUN.
- Pregnancy: several values, including ALP, albumin and creatinine, have different typical ranges.
- Sample handling: a difficult draw or a delay in processing can falsely raise potassium.
How the results fit together
- BUN and creatinine both raised may suggest dehydration or reduced kidney function. Your doctor may look at your eGFR and repeat the test.
- ALT and AST raised, with or without ALP and bilirubin, suggests a liver pattern that your doctor may investigate with more tests or an ultrasound.
- Low albumin can go with liver disease, kidney protein loss or poor nutrition. It also lowers the measured calcium, so doctors read the two together.
- Sodium, potassium and bicarbonate abnormal together can point to problems with fluid and acid-base balance that your doctor may want to recheck quickly.
- A raised fasting glucose is usually followed by a repeat test or an HbA1c.
When to contact a doctor
Mildly abnormal values with no symptoms are often repeated before anything else is decided. Contact your doctor soon if a result is flagged and you have:
- yellow skin or eyes, dark urine or pale stools
- swelling in the legs or face, or passing much less urine than usual
- muscle weakness, cramps or palpitations
- severe thirst with frequent urination
- vomiting or diarrhea that lasts more than a day or two
If your lab or doctor calls about a critical value, follow their advice the same day. Seek urgent care for confusion, fainting, a very irregular heartbeat or a seizure. In an emergency, call your local emergency number.
Frequently asked questions
Do I need to fast for a CMP?
Often yes. Glucose is meant to be measured after fasting for about 8 hours, and a recent meal can also change some other values. Water is usually allowed. Some labs run a CMP without fasting and interpret glucose differently, so follow the instructions given when the test was ordered.
What does a high creatinine level mean?
A high creatinine can be a sign of reduced kidney function, but dehydration, a high-protein meal, large muscle mass, creatine supplements and some medicines can also raise it. Your doctor will usually look at your eGFR and may repeat the test before drawing conclusions.
What do high ALT and AST mean?
Raised ALT and AST can be a sign of liver irritation, for example from fatty liver, viral hepatitis, alcohol or medicines. AST also rises with muscle injury and hard exercise. Mild rises are common and often rechecked. Your doctor may suggest more tests if the values stay high.
What is a normal fasting glucose on a CMP?
A fasting glucose of 70 to 99 mg/dL (3.9 to 5.5 mmol/L) is considered normal. Fasting values of 100 to 125 mg/dL (5.6 to 6.9 mmol/L) fall in the prediabetes range, and 126 mg/dL (7.0 mmol/L) or higher on repeat testing is in the diabetes range.