What is a comprehensive metabolic panel test?

Rachel Brown, MD

Family Medicine

Whether it’s performed after a regular well-check visit with your primary care physician because a doctor wants to check into specific health markers, or as part of the process of diagnosing an ongoing medical condition, you may be asked to undergo a comprehensive metabolic panel test or CMP. But what is a metabolic panel test, and what exactly can you and your doctor learn from the results?

Rachel Brown, MD, answered a few common questions about the comprehensive metabolic panel test.

What is a comprehensive metabolic panel test?

“The comprehensive metabolic panel is a specialized test that takes a closer look at electrolytes, kidney function, glucose and liver function,” said Dr. Brown. “It measures levels of 14 different substances within your blood and is a great noninvasive way to get a look at ongoing kidney and liver function.”

Why would a doctor order a comprehensive metabolic panel test?

“There are a few different reasons that you might be asked to give blood for a CMP test,” said Dr. Brown. “It may be ordered on a yearly basis for some folks with symptoms or chronic disease. The CMP isn’t recommended as a screening test by the U.S. Preventive Services Task Force.”

Reasons you might be asked to provide blood for a CMP include:

• Monitoring potential side effects of specific medications
• Checking on the body’s response to certain therapies
• Liver and kidney health (especially if taking some medications like ACE inhibitors
• To aid in diagnosing a suspected medical condition
• To monitor the potential progression of a diagnosed medical condition

What diseases can a CMP test help detect?

“The CMP can help detect diabetes, electrolyte or endocrine disorders, liver disease, kidney disease and a whole host of other medical conditions, as well,” said Dr. Brown. “It’s a good tool when it comes to taking a closer look at those specific health markers that can be affected by certain diseases.”

Do you need to fast before a metabolic panel?

Unless you are told to, you don’t need to avoid either food or drink before coming in for your metabolic panel. Some physicians may ask you to have a fasting glucose test, but they’ll let you know how to prepare.

What tests are included in a full metabolic panel?

The CMP shows the levels of 14 substances, including: 

• Albumin
• Alkaline phosphatase
• Aspartate aminotransferase
• Blood urea nitrogen
• Calcium
• Carbon dioxide
• Chloride
• Creatinine
• Glucose
• Potassium
• Sodium
• Total bilirubin
• Total protein

Will a doctor follow up with me about my metabolic panel results?

“Your doctor should absolutely follow up with you about your results,” said Dr. Brown. “Especially if they’re abnormal, in which case your doctor will want to talk to you about what those results indicate and what your next steps should be.”