Chem 7: Blood Chemistry Tests

What Your Basic Metabolic Panel Test Results Mean

Blood chemistry tests are often ordered before surgery. These help the medical team understand the patient's general health status.

The panel of tests is commonly called a chem 7. It looks at seven different substances in the blood. A chem 7 is also routinely performed after surgery. This helps make sure the person is well in the days following the operation.

This article discusses the chem 7 blood chemistry test and what it's looking for.

Vials in lab

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What is a Chem 7 Test?

The chem 7 test is known by a few different names, including:

  • Sequential multi-channel analysis
  • Computer 7 (SMAC7)
  • Metabolic 7

Most medical professionals call it a chem 7 or basic metabolic panel (BMP). A comprehensive metabolic panel (CMP) is similar but includes six additional tests. The seven tests included in the chem 7 panels are:

Recap

A chem 7 test looks at the levels of seven different substances in your blood. The results can help your medical team understand if you are well enough for surgery.

What to Expect From a Chem 7 Test

Your healthcare provider may order the chem 7 test several days before your procedure. It may also be ordered just before the procedure.

Blood will be drawn from a vein or taken from an intravenous (IV) line. The lab can usually return results very quickly.

The lab report will provide reference ranges for each of the seven substances. A result is normal if it falls between the high and low values in the range. Anything below or above the reference range is considered abnormal. There is some flexibility in the way the results are interpreted, based on:

  • Your age
  • Your general health, including any chronic medical conditions
  • Differences in the way results are interpreted from location to location

"Deranged" values are excessively high or low. If this is your result, you may need medical intervention before you can have surgery. You may also be unable to undergo surgery at all.

Your results may look different depending on where you are in the world.

In the United States, blood test results are typically described in standard metric values. For example:

  • Milliliters (mL)
  • Milligrams per deciliter (mg/dL)

Internationally, they are often described in metric concentration values. For example:

  • Millimoles per liter (mmol/L)
  • Micromoles per liter (umol/L)

Blood Urea Nitrogen (BUN)

The waste product urea is made when protein is broken down by the kidneys. Blood urea nitrogen (BUN) measures the amount of nitrogen in your blood that comes from urea. It is a measure of kidney function. A high level may indicate that the kidneys are not functioning normally.

The normal BUN values in adults fall in this range:

  • 8 to 23 mg/dL (U.S.)
  • 2.9 to 8.9 mmol/L (international)

Carbon Dioxide (CO2)

This test measures the amount of carbon dioxide in the blood. Most carbon dioxide is present in the form of bicarbonate. Bicarbonate is regulated by the lungs and kidneys. The test results tell doctors how well your body is regulating the bicarbonate in your blood.

The normal CO2 values for adults are between:

  • 22 to 28 mEq/L (U.S)
  • 22 to 29 mmol/L (international)

Creatinine

Creatinine is a waste product. It is produced by the body during normal muscle breakdown. High levels may point to a number of conditions, including:

Other conditions may also cause high creatinine.

Some medications can also cause a higher than normal level of blood creatinine. Low levels may be caused by conditions such as:

The normal creatinine values for adults fall in this range:

  • 0.6 to 1.2 mg/dL (U.S.)
  • 7.0 to 17.6 umol/L (international)

Glucose

The blood glucose test is a measure of your blood sugar. Blood sugar is also called glucose. High glucose levels can point to diabetes or another endocrine disorder. Your endocrine system helps regulate many of your body functions.

Various factors can influence blood glucose test results, including:

  • Some medications
  • The timing of the test in relation to meals

This is why the glucose test is usually done when you are fasting, or going without food.

The normal glucose values for adults are:

  • 70 to 110 mg/mL (U.S.)
  • 3.9 to 6.1 mmol/L (international)

Recap

The glucose test tells your medical team how high your blood sugar is. This test is usually done when you are fasting. 

Serum Chloride

The serum chloride (Cl) test measures the level of chloride in your blood. Chloride binds with electrolytes such as potassium and sodium. It helps maintain the proper pH balance of the blood. Chloride levels can vary widely if you are dehydrated or overhydrated.

Abnormal chloride levels can be a sign that the kidneys are not functioning properly. Heart failure and endocrine problems can also contribute to abnormal Cl results.

The normal serum chloride values in adults are:

  • 96 to 106 mEq/L (U.S.)
  • 96 to 106 mmol/L (international)

Serum Potassium

The serum potassium (K) test shows the level of potassium in the blood. Potassium plays a role in muscle contractions and cell function. Both high and low levels of potassium can cause problems with heart rhythm. This is why it is important to monitor potassium levels before and after surgery.

People who take diuretics regularly may require regular blood tests to monitor potassium levels. This is because some diuretics can cause the kidneys to excrete too much potassium.

The normal serum potassium values for adults run from:

  • 3.5 to 5.0 mEq/L (U.S.)
  • 3.5 to 5.1 mmol/L (international)

Serum Sodium

The serum sodium (Na) test measures the amount of sodium in the blood. Normally, excess sodium in the things you eat and drink is excreted by the kidneys. Sodium levels can fluctuate for a number of reasons, including:

  • Dehydration or overhydration
  • Diarrhea
  • Endocrine disorders
  • Trauma
  • Bleeding

The normal serum sodium values for adults are from:

  • 136 to 142 mEq/L (U.S.)
  • 135 to 145 mmol/L (international)

Summary

A chem 7 is a test that looks at seven different substances in the blood. It is often ordered before surgery. The results help your medical team know what your general health status is.

The test looks at your levels of blood urea nitrogen (BUN), carbon dioxide, creatinine, glucose, chloride, potassium, and sodium. It is usually done a few days before or right before surgery.

The blood is sent to a lab. The lab report shows your levels of each substance. Levels that are too high or too low point to a health problem. Abnormal results may be a reason to cancel or postpone surgery.

A Word From Verywell

Chem 7 is an important blood panel that poses little risk. You may have slight pain or bruising at the site where blood is drawn. Most symptoms go away quickly.

If the test is ordered several days before surgery, you may be required to fast. If you're not sure, ask your healthcare provider.

Frequently Asked Questions

  • Is a chem 7 the same as a basic metabolic panel?

    Yes, the chem 7 blood test is also called a basic metabolic panel or BMP. The seven blood markers tested include blood urea nitrogen (BUN), carbon dioxide, creatinine, glucose, serum chloride, serum potassium, and serum sodium. 

  • Is fasting required for a basic metabolic panel?

    Typically yes, but not always. Fasting eight hours before drawing bloodwork for the basic metabolic panel is recommended but not always practical. For example, if the test is taken at the doctor's office or hospital without prior planning, fasting before the test may not be possible.

    Blood glucose levels—one of the seven tests in the panel—should be measured fasting. It is used to screen for diabetes and should be below 100 mg/dL in non-diabetics. Blood glucose levels can rise after eating and be as high as 140 mg/dL in people without diabetes.

  • What is the difference between basic and comprehensive metabolic panel?

    A comprehensive metabolic panel (CMP) includes 14 tests—the chem 7 plus seven more tests. Also called chem 14, it includes liver functioning tests and provides a more in-depth look at your overall health. 

    Sometimes mistakenly called a complete metabolic panel, the CMP includes:

    • Alanine aminotransferase (ALT)
    • Albumin
    • Alkaline phosphatase (ALP)
    • Aspartate aminotransferase (AST)
    • Bilirubin
    • Blood urea nitrogen (BUN)
    • Calcium
    • Carbon dioxide
    • Chloride
    • Creatinine
    • Glucose
    • Potassium
    • Sodium
    • Total protein
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9 Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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