To give your healthcare provider important information about your body's metabolism, including the current status of your kidneys as well as electrolyte and acid/base balance and level of blood glucose
Basic Metabolic Panel (BMP)
As part of a routine health exam; when you are hospitalized, in the emergency room
A blood sample drawn from a vein in your arm
You may be instructed to fast (nothing but water) for 10 to 12 hours prior to the blood draw. Depending on the reason for ordering the BMP, it may be drawn after fasting or on a random basis. Follow any instructions you are given.
The basic metabolic panel (BMP) is a frequently ordered panel of 8 tests that gives a healthcare practitioner important information about the current status of a person's metabolism, including health of the kidneys, blood glucose level, and electrolyte and acid/base balance. Abnormal results, and especially combinations of abnormal results, can indicate a problem that needs to be addressed.
The BMP includes the following tests:
- Glucose - energy source for the body; a steady supply must be available for use, and a relatively constant level of glucose must be maintained in the blood.
- Calcium - one of the most important minerals in the body; it is essential for the proper functioning of muscles, nerves, and the heart and is required in blood clotting and in the formation of bones.
- Sodium - vital to normal body processes, including nerve and muscle function
- Potassium - vital to cell metabolism and muscle function
- CO2 (carbon dioxide, bicarbonate) - helps to maintain the body's acid-base balance (pH)
- Chloride - helps to regulate the amount of fluid in the body and maintain the acid-base balance
- BUN (blood urea nitrogen) - waste product filtered out of the blood by the kidneys; conditions that affect the kidney have the potential to affect the amount of urea in the blood.
- Creatinine – waste product produced in the muscles; it is filtered out of the blood by the kidneys so blood levels are a good indication of how well the kidneys are working.
- How is it used?
The basic metabolic panel (BMP) is used to check the status of a person's kidneys and their electrolyte and acid/base balance, as well as their blood glucose level – all of which are related to a person's metabolism. It can also be used to monitor hospitalized patients and people with certain known conditions, such as hypertension and hypokalemia.
If a health practitioner is interested in following two or more individual BMP components, he or she may order the entire BMP because it offers more information. Alternatively, the healthcare provider may order individual tests when monitoring, such as a follow-up glucose, potassium, or calcium, or order an electrolyte panel to monitor sodium, potassium, chloride, and CO2. If a health practitioner wants more information, he or she may order a comprehensive metabolic panel (CMP), a group of 14 tests that includes those in the BMP.
- When is it ordered?
A BMP may be ordered as part of a routine health exam.
The panel is also often ordered in the hospital emergency room setting because its components give health practitioners important information about the current status of a person's kidneys, electrolyte and acid/base balance, and blood glucose and calcium levels. Significant changes in these test results can indicate acute problems, such as kidney failure, insulin shock or diabetic coma, respiratory distress, or heart rhythm changes.
- What does the test result mean?
Results of the tests that are part of the BMP are typically evaluated together to look for patterns of results. A single abnormal test result may mean something different than if several test results are abnormal.
Out-of-range results on any of the tests included in the BMP can be due to a variety of different conditions, including kidney failure, breathing problems, and diabetes-related complications. Typically, if any results are out-of-range, one or more follow-up tests are performed to help pinpoint the cause and/or help establish a diagnosis.
See the articles on the individual tests for more detailed information about each one, including their reference ranges.
- CO2 (carbon dioxide, bicarbonate)
- BUN (blood urea nitrogen)
- Is there anything else I should know?
A variety of prescription and over-the-counter drugs can affect the results of the components of the BMP. Be sure to tell your healthcare provider about any medications you are taking. Likewise, it is important to give a complete history as many other factors can also affect the interpretation of your results.
- How is the BMP different than the CMP and why would my doctor order one over the other?
The BMP has 8 tests; the comprehensive metabolic panel (CMP) is a made up of 14 tests – the 8 from the BMP as well as 2 protein tests (albumin and total protein) and 4 liver tests (ALP, ALT, AST, and bilirubin). 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.
- One of the results from my BMP is slightly out of range. What does this mean?
The results of your BMP 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 for 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.
For more, read the articles on Reference Ranges and What They Mean and How Reliable is Laboratory Testing?