1. How is the CMP different than the BMP and why would my doctor order one over the other?
The CMP is made up of 14 tests; the basic metabolic panel (BMP) is a subset of those and has 8 tests. It does not include the liver (ALP, ALT, AST, and bilirubin) and protein (albumin and total protein) tests. A healthcare provider may order a CMP rather than a BMP if he or she wants to get a more complete picture of the status of a person's organ function or to check for specific conditions, such as diabetes or liver or kidney disease.
2. One of the results from my CMP is slightly out of range. What does this mean?
The results of your CMP are interpreted by your healthcare provider within the context of other tests that you have had done as well as other factors, such as your medical history. A single result that is slightly high or low may or may not have medical significance. There are several reasons why a test result may differ on different days and why it may fall outside a designated reference range.
Biological variability (different results in the same person at different times): If a health practitioner runs the same test on you on several different occasions, there's a good chance that one result will fall outside a reference range even though you are in good health. For biological reasons, your values can vary from day to day.
Individual variability (differences in results between different people): References ranges are usually established by collecting results from a large population and determining from the data an expected average (mean) result and expected differences from that average (standard deviation). There are individuals who are healthy but whose tests results, which are normal for them, do not always fall within the expected range of the overall population.
Thus, a test value that falls outside of the established reference range supplied by the laboratory may mean nothing significant. Generally, this is the case when the test value is only slightly higher or lower than the reference range and this is why a health practitioner may repeat a test on you and why he or she may look at results from prior times when you had the same test performed.
However, a result outside the range may indicate a problem and warrant further investigation. Your healthcare provider will evaluate your test results in the context of your medical history, physical examination, and other relevant factors to determine whether a result that falls outside of the reference range means something significant for you.
This article was last reviewed on August 30, 2012. | This article was last modified on March 16, 2015.
The review date indicates when the article was last reviewed from beginning to end to ensure that it reflects the most current science. A review may not require any modifications to the article, so the two dates may not always agree.
The modified date indicates that one or more changes were made to the article. Such changes may or may not result from a full review of the article, so the two dates may not always agree.