How the Test is Performed

A blood sample is needed. For information on how this is done, see: Venipuncture

How to Prepare for the Test

You should not eat or drink for 8 hours before the test.

How the Test Will Feel

When the needle is inserted to draw blood, some people feel moderate pain, while others feel only a prick or stinging sensation. Afterward, there may be some throbbing.

Why the Test is Performed

This test will give your doctor information about:

• How your kidneys and liver are working
• Blood sugar, cholesterol, and calcium levels
• Sodium, potassium, and chloride levels (called electrolytes)
• Protein levels

Your doctor may order this test during a yearly exam or routine checkup.

Normal Results

• Albumin: 3.9 to 5.0 g/dL
• Alkaline phosphatase: 44 to 147 IU/L
• ALT (alanine aminotransferase): 8 to 37 IU/L
• AST (aspartate aminotransferase): 10 to 34 IU/L
• BUN (blood urea nitrogen): 7 to 20 mg/dL
• Calcium: 8.5 to 10.9 mg/dL
• Chloride: 96 - 106 mmol/L
• CO2 (carbon dioxide): 20 to 29 mmol/L
• Creatinine: 0.8 to 1.4 mg/dL **
• Glucose test: 100 mg/dL
• Potassium test: 3.7 to 5.2 mEq/L
• Sodium: 136 to 144 mEq/L
• Total bilirubin: 0.2 to 1.9 mg/dL
• Total protein: 6.3 to 7.9 g/dL

**Note: Normal or healthy values for creatinine can vary with age. Normal value ranges for all tests may vary slightly among different laboratories. Talk to your doctor about the meaning of your specific test results.

The examples above show the common measurements for results for these tests. Some laboratories use different measurements or may test different specimens.

Key to abbreviations:

• IU = international unit
• L = liter
• dL = deciliter = 0.1 liter
• g/dL = gram per deciliter
• mg = milligram
• mmol = millimole
• mEq = milliequivalents

What Abnormal Results Mean

Abnormal results can be due to a variety of different medical conditions, including kidney failure, breathing problems, and diabetes-related complications. See the individual tests listed in the normal values section for detailed information.

Risks

There is very little risk involved with having your blood taken. Veins and arteries vary in size from one patient to another and from one side of the body to the other. Taking blood from some people may be more difficult than from others.

Other risks associated with having blood drawn are slight but may include:

• Excessive bleeding
• Fainting or feeling light-headed
• Hematoma (blood accumulating under the skin)
• Infection (a slight risk any time the skin is broken)

Alternative Names

Metabolic panel - comprehensive; Chem-20; SMA20; Sequential multi-channel analysis with computer-20; SMAC20; Metabolic panel 20

Updated: 4/30/2012

Reviewed by: A.D.A.M. Editorial Team: David Zieve, MD, MHA, and David R. Eltz. Previously reviewed by David C. Dugdale, III, MD, Professor of Medicine, Division of General Medicine, Department of Medicine, University of Washington School of Medicine (2/20/2011).