Comprehensive Metabolic Panel (CMP)

What is a comprehensive metabolic panel (CMP)?

A comprehensive metabolic panel (CMP) is a blood sample test that measures 14 different substances in your blood. It provides important information about your body's chemical balance and metabolism (how your body transforms the food you eat into energy).

Healthcare providers often use a CMP as a routine blood test and to help diagnose, screen for or monitor certain health conditions.

What tests are in a comprehensive metabolic panel (CMP)?

A CMP measures the following substances in your blood:

• Glucose: This is a type of sugar that provides energy for your body and brain. Glucose is also known as blood sugar. Elevated fasting blood glucose is often a sign of Type 2 diabetes. Very high glucose levels, whether fasting or not, usually indicate Type 1 diabetes.
• Calcium: Calcium is one of the most important and common minerals in your body. While most of your calcium is stored in your bones, you need calcium in your blood as well. Blood calcium is essential for proper functioning of your nerves, muscles and heart.
• Total protein: This is a measurement of the total amount of albumin and globulins, which are proteins in your blood.
• Bilirubin: This is a waste product that’s made from the breakdown of red blood cells. Your liver is in charge of removing bilirubin from your body.
• BUN (blood urea nitrogen): This is a measurement of urea nitrogen, which is a waste product that your kidneys help remove from your blood.
• Creatinine: This is a byproduct of muscle activity. It’s a waste product that your kidneys filter and remove from your blood.
• Albumin: This is a protein that your liver makes. It transports important substances through your bloodstream and keeps fluid from leaking out of your blood vessels.

A CMP also measures the following four electrolytes. Electrolytes are minerals that carry an electric charge when they are dissolved in a liquid. These electrolytes in your blood control nerve and muscle function and maintain the acid-base balance (pH balance) of your blood and your water balance.

• Sodium: Most of your sodium comes from the food you eat, and your kidneys help regulate your body’s sodium levels.
• Potassium: Potassium comes from the food you eat and is present in all tissues of your body.
• Bicarbonate: Bicarbonate indicates the amount of carbon dioxide (CO₂) in your blood.
• Chloride: Chloride functions along with sodium, potassium and bicarbonate to control many processes in your body.

A CMP also measures the following three liver enzymes. Enzymes are substances that act as a catalyst and allow certain bodily processes to happen.

• Alkaline phosphatase (ALP).
• Alanine transaminase (ALT).
• Aspartate aminotransferase (AST).

What is a comprehensive metabolic panel used for?

Healthcare providers often use a comprehensive metabolic panel (CMP) to get a broad assessment of your overall physical health. With 14 individual measurements, it can check several body functions and processes, including:

• Your liver and kidney health.
• Your blood sugar levels.
• The acid and base balance in your blood.
• Your fluid and electrolyte balance.

Depending on the situation, your provider can have you undergo a CMP for the following reasons:

• Diagnosis: A CMP can help your provider diagnose certain medical conditions.
• Screening: Screening means attempting to find health issues before you have symptoms. Routine screening helps find certain conditions in their early stages. Since it contains 14 different measurements, providers often use a CMP as a part of routine health checkups.
• Monitoring: If you have a certain medical condition, a CMP can help your provider determine if your treatment is working. CMPs can also help check for side effects of certain medications, especially those that can affect your liver or kidneys.

Why do I need a comprehensive metabolic panel?

A comprehensive metabolic panel (CMP) can provide helpful information in many different situations, including:

• If you’re experiencing symptoms related to kidney, liver and/or metabolism issues.
• If you’re experiencing a general symptom, such as fatigue. Since a CMP measures several important aspects of your blood, it can help determine or rule out certain causes of a common symptom.
• If you had a prior test result that was abnormal, your provider may want to test again to see if your levels have changed or remain abnormal.
• If you’re taking a treatment for a medical condition, your provider may test to see if the treatment is working.
• If you’re starting a new medication that can affect your kidney or liver function.

What’s the difference between a comprehensive metabolic panel and a basic metabolic panel?

A basic metabolic panel (BMP) includes eight of the 14 tests in a comprehensive metabolic panel (CMP). A BMP doesn’t include the liver enzyme and protein tests. Your healthcare provider may have you undergo a CMP or a BMP depending on your health history and needs. Both panels are considered routine blood tests.

Who performs a comprehensive metabolic panel (CMP)?

A healthcare provider called a phlebotomist usually performs blood draws, including those for a comprehensive metabolic panel (CMP), but any healthcare provider trained in drawing blood can perform this task. A provider then sends the sample to the lab where a medical laboratory scientist prepares the samples and performs the tests on machines known as analyzers.

Do I need to fast for a comprehensive metabolic panel (CMP)?

In order to prepare, you’ll likely need to avoid eating or drinking (fast) for 10 to 12 hours before your comprehensive metabolic panel blood test so that the glucose reflects a fasting sample, instead of sugars from food you’ve eaten. Your healthcare provider will give you specific instructions when they order the test for you.

What should I expect during my comprehensive metabolic panel blood test?

You can expect to experience the following during a blood test, or blood draw:

• You’ll sit in a chair, and a healthcare provider will check your arms for an easily accessible vein. This is usually in the inner part of your arm on the other side of your elbow.
• Once they’ve located a vein, they’ll clean and disinfect the area.
• They’ll then insert a small needle into your vein to take a blood sample. This may feel like a small pinch.
• After they insert the needle, a small amount of blood will collect in a test tube.
• Once they have enough blood to test, they’ll remove the needle and hold a cotton ball or gauze on the site to stop any bleeding.
• They’ll place a bandage over the site, and you’ll be finished.

The entire procedure usually takes less than five minutes.

What should I expect after my comprehensive metabolic panel blood test?

After a healthcare provider has collected your blood sample, they’ll send it to a laboratory for testing. Once the test results are back, your healthcare provider will share them with you.

What are the risks of a comprehensive metabolic panel blood test?

Blood tests are a very common and essential part of medical testing and screening. There’s very little risk to having blood tests. You may have slight tenderness or a bruise at the site of the blood draw, but this usually resolves quickly.

What do the results of a comprehensive metabolic panel mean?

Blood test reports, including comprehensive metabolic panel test reports, usually provide the following information:

• The name of the blood test or what was measured in your blood.
• The number or measurement of your blood test result.
• The normal measurement range for that test.
• Information that indicates if your result is normal or abnormal, or high or low.

If any single CMP result or a combination of results are not normal, it may indicate — but not guarantee — many different health conditions, including:

• Liver disease.
• Kidney disease.
• Diabetes.
• High blood pressure (hypertension).

If you have an abnormal result, your healthcare provider will likely have you undergo additional tests to confirm or rule out a specific diagnosis. If you have questions about your results, don’t be afraid to talk to your provider.

Should I be concerned if I have abnormal comprehensive metabolic panel test results?

If one of your CMP results is abnormal, it doesn't necessarily mean that you have a medical condition. Other factors, such as diet, certain medications and health conditions can affect your test results. There could’ve also been an error in the collection, transport or processing of the test.

Your healthcare provider will take into consideration your medical history and current medications as well as your results and let you know if you need to undergo further testing.

When should I know the results of the test?

In most cases, you should have your comprehensive metabolic panel test results within one or two days, though it could take longer.

A note from Cleveland Clinic

A comprehensive metabolic panel is a helpful and common blood test that broadly assesses your physical health. Know that having an abnormal level in one of your CMP results doesn’t necessarily mean you have a medical condition. Approximately 1 in 20 healthy people will have an abnormal test result. Many other factors can affect your results. Your healthcare provider will let you know if you need to undergo further tests to determine the cause of the abnormal level. Don’t be afraid to ask your provider questions. They’re there to help you.