What Is a Comprehensive Metabolic Panel?
Comprehensive metabolic panel (CMP) is a series of blood tests that give your doctor a snapshot of your body’s chemistry and the way it’s using energy (your metabolism). It’s also called a chemistry panel of Chem-14, chemistry 14, or chemistry screen.
Most people get a CMP as part of their yearly checkup. The doctor might also want one to check you for problems, keep track of any chronic conditions you have, or make sure certain medications aren’t hurting your liver or kidneys. They might tell you not to eat or drink anything except water for up to 12 hours before you get this test.
The CMP can tell your doctor:
- How your kidneys and liver are working
- Your blood sugar levels
- Your electrolyte levels
- How much protein is in your blood
- The balance of acid and base in your blood
- How your metabolism is working
The doctor may give you a basic metabolic panel (BMP) instead of a CMP based on your health history and your needs. It includes eight of the same tests as CMP. It doesn’t include the liver and protein tests.
Comprehensive Metabolic Panel Procedure
A nurse or doctor will use a needle to take a blood sample from a vein in your arm. They’ll collect the blood in a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than 5 minutes.
You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.
Comprehensive Metabolic Panel Results
The doctor will look at all the tests together to check for patterns. The combination of patterns can tell there’s a concern you could have liver or kidney disease.
If you’re in the hospital, the doctor may do daily tests. If you aren’t but you have a disease like diabetes or kidney disease, you may go to the doctor’s office or a clinic every few months for tests.
Your report will usually have one column called a “reference range” and another for your results. If your results are inside the reference range, they’re normal. If they’re above or below it, they’re considered abnormal.
A lot of things can affect a CMP, such as:
- Medications you might be taking, like steroids, insulin, and hormones
- Eating or drinking before the test
- Exercising before the test
- Damage to blood cells during the collection or processing related to the blood test.
If any of your results are not what they should be, your doctor might ask you to come back for more tests. This will help your doctor figure out if there’s a true problem or not.
Normal comprehensive metabolic panel results
Reference ranges depend on the lab that handles your blood tests. Why? Because different labs use their own special equipment. They also have different ways of analyzing your blood. General ranges for what’s considered normal are listed below. But always go by the ranges that are on your report because that’s what your doctor will use.
There are more than a dozen tests in a CMP, but your doctor may change a few to look for certain clues about what’s going on in your body. Listed below are the main tests usually included in a CMP:
CMP liver tests
These check three substances your liver makes: ALP, ALT, and AST. They also check bilirubin, a waste product of your liver. Normal ranges are:
- ALP (alkaline phosphatase): 44-147 international units per liter (IU/L)
- ALT (alanine aminotransferase): 7-40 IU/L
- AST (aspartate aminotransferase): 10-34 IU/L
- Bilirubin: 0.3-1.9 milligrams per deciliter (mg/dL)
CMP kidney tests
- BUN (blood urea nitrogen): 6-20 mg/dL
- Creatinine: 0.6-1.3 mg/dL
CMP electrolyte test
These help your body balance its fluids. They also help control your heartbeat and how your muscles and your brain work. Abnormal results could mean you have heart disease or kidney disease, or that you’re dehydrated. Normal ranges are:
CMP protein test
The CMP tests albumin, the main protein made by your liver, and the proteins in your blood in general. Proteins are important for healthy muscles, bones, blood, and organs. If these come back low, it could mean liver or kidney disease or a problem with nutrition. Normal ranges are:
- Albumin: 3.4-5.4 grams per deciliter (g/dL)
- Total protein: 6.0-8.3 g/dL
CMP glucose test
This is also commonly called a blood sugar test. If your levels are high, it could mean you have diabetes. If they’re too low, you could have a condition called hypoglycemia. The normal range is 70-99 mg/dL.
CMP calcium test
This is important for healthy muscles, nerves, and hormones. If calcium is abnormal, you might have a hormone imbalance or problems with your kidneys, bones, or pancreas. The normal range is 8.6-10.2 mg/dL.