Differences in a CMP and a BMP

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The two metabolic tests that doctors commonly order are the CMP and the BMP. CMP is the medical abbreviation for Comprehensive Metabolic Profile and BMP is the abbreviation for Basic Metabolic Profile. The CMP is usually comprised of a group of 14 specific tests that tell about the current status of your kidneys, liver, and electrolyte and acid/base balance, as well as your blood sugar and blood proteins. The BMP only contains eight of the metabolic tests.

The Comprehensive Metabolic Profile, CMP

The blood electrolytes measured are sodium, potassium, chloride and carbon dioxide. Imbalances in these tests indicate an abnormal acid/base balance in the blood. The next test in the profile is the test for glucose. Abnormal glucose levels are associated with diabetes. Blood urea nitrogen and creatinine are analyzed to indicate the health of the liver and kidneys. A blood calcium level is tested to look for bone and muscle health.

The CMP goes on to check levels of liver function by analyzing the blood bilirubin and liver enzyme tests. These enzymes are called AST, ALT and ALP. By checking the liver enzymes, a doctor can monitor drug therapy, hepatitis or other metabolic functions.

Two other blood tests included in the CMP, but not in the BMP, are the total protein and albumin levels. Abnormalities in the protein levels can indicate a digestion or absorption problem in the digestive tract.

The Basic Metabolic Profile, BMP

Both CMP's and BMP's are done on fasting blood specimens for best results. The BMP is a quick and easy monitor for the acid/base balance of the blood, for a screening test for diabetes and a screening test for kidney and liver function. It is less expensive for the patient, yet still indicates the current state of metabolic normality or abnormality. The BMP will generally be included in a yearly physical exam.

Doctors base the decision to order a BMP instead of a CMP depending on several factors including general state of health, drug therapy and any symptoms a patient has.

Comparing the Differences of the CMP and BMP

On one hand the CMP is a more thorough blood test, but it is more expensive and takes a bit longer to run. The BMP is a common screening test done on an emergency basis, as well as a standard order, for quickly determining the present state of overall health. Both are standard chemistry lab tests and require the same amount of blood sample. Doctors usually order the BMP first and add the liver function testing if necessary.