An electrolyte panel is a blood test that measures several different substances in the body. It can provide important information about your hydration and nutrition, kidney function, and overall health.
This test has many uses. Your provider may order an electrolyte panel as part of your regular checkup, to monitor the levels of specific electrolytes, or to help diagnose the cause of new or unexplained symptoms.
Your electrolyte levels may change if you’re taking certain medications or have certain medical conditions. This test helps to ensure that your electrolyte levels remain in the normal range since these minerals affect key bodily functions.
An electrolyte panel is a blood test. It measures the levels of the body’s main electrolytes that play an important role in many bodily functions, such as heart rhythm, muscle contraction, and brain function. It also includes tests to assess kidney function and hydration status. We’ll explain which substances an electrolyte panel measures, common reasons providers order them, and how to read your results.
An electrolyte panel (also referred to as a “metabolic panel”) measures electrolytes and other substances in the blood that play important roles in your overall health. These include:
Sodium (Na): plays a key role in fluid balance and brain function
Potassium (K): regulates the heartbeat as well as nerve and muscle activity
Chloride (Cl): contributes to fluid balance and acid-base levels in the blood
Carbon dioxide (CO2): indicates how well your body is maintaining the right acid-base balance
Blood urea nitrogen (BUN) and creatinine (Cr): two waste products that provide a measure of kidney function
Glucose: also known as “blood sugar”
Together, these components make up a basic metabolic panel (BMP). There’s also a more extensive panel that providers can order if needed.
In order to capture a more detailed picture of your health, your provider may order a more extensive electrolyte panel called a “comprehensive metabolic panel” (CMP). A CMP includes all of the components of a basic panel, along with a few more electrolytes and tests to evaluate your liver function.
A CMP includes these additional tests:
Total protein: a measurement of nutritional status as well as liver and kidney health
Calcium (Ca): a mineral important for bone and muscle health
Magnesium (Mg): a mineral that supports nerve and muscle function
Phosphate (PO4): another mineral that supports nerve, bone, and muscle health
A CMP also includes several tests that assess liver health and function. These include:
Alanine transaminase (ALT): a liver enzyme that breaks down protein
Aspartate transaminase (AST): a liver enzyme that supports metabolism
Alkaline phosphatase: an enzyme found in the liver, bones, digestive tract, and kidneys that helps support digestion and bone health
Total bilirubin: a byproduct of red blood cell breakdown that the liver processes
Albumin: a protein the liver makes
An electrolyte panel can be a useful lab test for many different reasons. Your provider may order one as part of your regular checkup or just to get a general picture of your overall health. Your provider may also order an electrolyte panel to:
Monitor kidney function
Monitor liver function
Check your hydration or nutrition status if there are concerns about dehydration or malnutrition
Check the electrolytes that are important for healthy heart function, like potassium, magnesium, and calcium
Check the electrolytes for healthy brain function, like sodium
Monitor glucose and electrolytes in someone with diabetes
Understand symptoms that are hard to explain, like weakness, fatigue, lack of appetite, or dizziness
Help diagnosis a specific medical condition, such as certain endocrine (hormone) conditions, kidney disease, or liver disease
Your provider may also use this test to monitor levels that medications can affect. Common medications that affect electrolyte levels and kidney function include:
Antifungal medications, like Lamisil (terbinafine)
Cancer or rheumatoid arthritis treatments, such as methotrexate
There’s a general range of acceptable values for each of the electrolytes measured in a panel. Certain labs may use different cut-off values, which is important to note when interpreting your test results. When you look at your results, it will likely include the normal range for that specific lab.
Standard or normal ranges for a BMP are:
Na: 134 to 144 mmol/L
K: 3.5 to 5.2 mmol/L
Cl: 96 to 106 mmol/L
CO2: 20 to 29 mmol/L
BUN: 9 to 23 mg/dL
Cr: 0.57 to 1.00 mg/dL
Glucose: 65 to 99 mg/dL
And an example of normal ranges for the values included in a CMP are:
Total protein: 6.0 to 8.5 g/dL
Albumin: 3.8 to 4.8 g/dL
Ca: 8.7 to 10.2 mg/dL
Mg: 1.3 to 2.1 mEq/L
PO4: 2.8 to 4.5 mg/dL
ALT: 0 to 32 IU/L
AST: 0 to 40 IU/L
Alkaline phosphatase: 39 to 117 IU/L
Total bilirubin: 0 to 1.2 mg/dL
It can be confusing and scary to receive lab results that are flagged as abnormal, especially if you haven’t had a chance to talk to your provider. Remember that not all abnormal values are a cause for concern, and it’s common for many of these values to fluctuate from day to day. And some of the abnormalities may not even be accurate. Lab errors happen, and sometimes your provider may recommend repeating a test to make sure that it’s right.
Here’s another thing to keep in mind when interpreting the status of your health: It’s generally more useful to look at lab value trends over time — rather than focusing on one test or data point. It may be tempting to jump to a conclusion about what a high or low number may mean, but it helps to consider the bigger picture. When you discuss the results of your labs with your provider, they can help put them into context and compare them to your past lab results.
Electrolytes are important substances that affect key bodily functions. Your doctor may measure your electrolyte levels during your routine health checkup to ensure that they are all within the normal range. Monitoring these levels may also be important if you have a certain medical condition, or if you’re taking certain medications that affect them. Oftentimes, monitoring the levels over time is more useful than an isolated number. Consult your provider if you’re concerned about a lab level, and they can help you interpret what it means for you and your health.
NHS. (2018). Electrolyte test.
Kids Health. (n.d.). Blood test: Comprehensive metabolic panel (CMP).