Chemistry 7: Blood Chemistry Test

Blood chemistry tests are usually done before surgery. These help the medical team understand the general health of the patient.

The test panel is often referred to as Chemistry 7. It looks at seven different substances in the blood. Chemistry 7 is also often performed after surgery. This helps ensure that the person is in good health for a few days after the procedure.

This article discusses the chem 7 blood chemistry test and what it looks for.

What is the Chemistry 7 test?

chem 7 tests have several different names, including:

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

Most medical professionals call this chem 7 or the basic metabolome (BMP). The Comprehensive Metabolome (CMP) is similar, but includes six additional tests. The seven tests included in the chem 7 panel are:

  • Blood urea nitrogen (BUN)
  • carbon dioxide
  • Creatinine
  • glucose
  • serum chloride
  • serum potassium
  • serum sodium


The Chemistry 7 test looks at the levels of seven different substances in the blood. The results can help your medical team know if you are good enough for surgery.

What to Expect from the Chem 7 Test

Your healthcare provider may order a chem 7 test a few days before your surgery. It can also be ordered prior to the procedure.

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

Laboratory reports will provide reference ranges for each of the seven substances. If the result is between the high and low values ​​of the range, the result is normal. Anything below or above the reference range is considered abnormal. There is some flexibility in how the results are interpreted, based on:

  • your age
  • your general health, including any chronic medical conditions
  • Different locations interpret results differently

The “outlier” value is too high or too low. If this is your result, you may need medical intervention before surgery. You may also not be able to have surgery at all.

Depending on where in the world you are, your results may vary.

In the U.S., blood test results are often described as standard measures. E.g:

  • milliliter (mL)
  • milligrams per deciliter (mg/dL)

Internationally, they are usually described in metric concentration values. E.g:

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

Blood urea nitrogen (BUN)

When protein is broken down by the kidneys, waste urea is produced. Blood urea nitrogen (BUN) measures the amount of nitrogen in the blood from urea. It is a measure of kidney function. High levels may indicate abnormal kidney function.

Normal BUN values ​​for adults are in this range:

  • 8 to 23 mg/dL (US)
  • 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 exists in the form of bicarbonate. Bicarbonate is regulated by the lungs and kidneys. Test results tell your doctor how well your body regulates bicarbonate in your blood.

Normal carbon dioxide values ​​for adults are between:

  • 22 to 28 mEq/L (US)
  • 22 to 29 mmol/L (international)


Creatinine is a waste product. It is produced by the body during normal muscle breakdown. High levels can indicate a variety of conditions, including:

  • renal impairment
  • low blood pressure
  • hypertension

Other conditions can also cause high creatinine.

Some medications can also cause blood creatinine levels to be higher than normal. Low levels can be caused by:

  • advanced muscular dystrophy
  • muscle weakness severe
  • overhydration

Normal creatinine values ​​for adults are in this range:


A blood sugar test is a measure of your blood sugar. Blood sugar is also called glucose. High glucose levels may point to diabetes or other endocrine disorders. Your endocrine system helps regulate many of your bodily functions.

A variety of factors can affect blood sugar test results, including:

  • some drugs
  • Meal-Related Test Times

This is why a glucose test is usually done when you are fasting or not eating.

Normal blood sugar levels for adults are:

  • 70 to 110 mg/ml (US)
  • 3.9 to 6.1 mmol/L (international)


A glucose test tells your healthcare team how high your blood sugar is. This test is usually done while you are fasting.

serum chloride

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

Abnormal chloride levels may indicate abnormal kidney function. Heart failure and endocrine problems can also lead to abnormal Cl results.

Normal serum chloride values ​​in adults are:

  • 96 to 106 mEq/L (US)
  • 96 to 106 mmol/l (international)

serum potassium

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

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

Normal serum potassium values ​​in adults are derived from:

  • 3.5 to 5.0 mEq/L (US)
  • 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 your diet is excreted by the kidneys. Sodium levels can fluctuate for a number of reasons, including​​:

  • dehydration or overhydration
  • diarrhea
  • endocrine disorders
  • trauma
  • bleeding

Normal serum sodium values ​​in adults are derived from:

  • 136 to 142 mEq/L (US)
  • 135 to 145 mmol/l (international)


Chemistry 7 is a test that checks for seven different substances in the blood. It is usually ordered before surgery. The results help your healthcare team understand your general health.

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

Blood is sent to the laboratory. Lab reports show your levels of each substance. Levels that are too high or too low can indicate a health problem. Abnormal results may be the reason for the cancellation or postponement of surgery.

VigorTip words

Chem 7 is an important blood test kit with very little risk. There may be minor pain or bruising where the blood was drawn. Most symptoms go away quickly.

If the test was ordered a few days before surgery, you may need to fast. Consult your healthcare provider if you are unsure.

Frequently Asked Questions

  • Is chem 7 the same as the Basic Metabolism panel?

    Yes, the chem 7 blood test is also known as the basic metabolome or BMP. The seven blood markers tested included blood urea nitrogen (BUN), carbon dioxide, creatinine, glucose, serum chloride, serum potassium, and serum sodium.

  • Does the basal metabolome require fasting?

    Usually yes, but not always. Fasting 8 hours before blood draws for the basal metabolome is recommended, but not always feasible. For example, if the test is performed in a doctor’s office or hospital without prior planning, it may not be possible to fast before the test.

    Blood sugar levels — one of the seven tests in the panel — should be measured on an empty stomach. It is used to screen for diabetes and should be less than 100 mg/dL in non-diabetic patients. Blood sugar levels rise after eating, up to 140 mg/dL in people without diabetes.

  • What is the difference between the Basal Metabolism Panel and the Comprehensive Metabolism Panel?

    The Comprehensive Metabolome (CMP) consists of 14 tests – 7 for chemistry and another 7 tests. Also known as chem 14, it includes liver function tests and provides a deeper understanding of your overall health.

    Sometimes incorrectly referred to as the complete metabolic panel, 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