Electrolyte Panel

What is an electrolyte panel?

An electrolyte panel is a blood test that measures the levels of seven electrolytes in your blood. Certain health conditions can cause electrolyte levels to become too high or low. This is called an electrolyte imbalance.

Why would I need an electrolyte panel?

You may get an electrolyte panel as part of a routine blood test or physical exam, or as part of a comprehensive metabolic panel (CMP) or basic metabolic panel (BMP).

Providers typically order one to:

• Diagnose conditions that cause electrolyte imbalances
• Monitor if treatment for electrolyte imbalance is working
• Evaluate if certain symptoms are due to an electrolyte imbalance

The following health conditions can cause high or low electrolyte levels:

• Burns
• Dehydration
• Diabetes
• Cardiovascular disease
• High blood pressure
• Kidney disease
• Liver disease like cirrhosis
• Overhydration or water intoxication
• Certain medications like antibiotics, diuretics or corticosteroids

What is included in an electrolyte panel?

An electrolyte panel checks the levels of multiple minerals in your blood. It could include some or all of the following:

• Sodium: Controls fluid levels and helps with nerve and muscle function.
• Potassium: Supports heart, nerve and muscle function, as well as metabolism.
• Chloride: Helps maintain healthy blood pressure and body fluid levels.
• Bicarbonate: Maintains a healthy balance of acids and basic alkaline compounds in your blood (acid-base balance). It also moves carbon dioxide through your bloodstream.
• Calcium: Supports your musculoskeletal system (bones and muscles), nervous system and circulatory system.
• Magnesium: Helps with nerve and muscle function and promotes the growth of bones and teeth (skeletal system).
• Phosphate: Develops healthy teeth and bones and helps with nerve and muscle function.

Some electrolyte tests measure only one specific type of electrolyte. For example, your provider may just check your potassium levels.

How should I prepare for an electrolyte blood test?

These steps can help a blood draw go smoothly:

• Stay hydrated: Drink plenty of fluids before the test to help blood flow more easily through blood vessels.
• Avoid nicotine: Don’t smoke (including vaping) before a blood draw. Nicotine constricts (narrows) blood vessels, making it more difficult to insert the needle into a vein.
• Speak up: Let your provider know if you have a fear of needles or a fear of blood. There are steps they can take to make the blood draw easier for you.

Do you need to fast for an electrolyte panel?

Typically, you don’t have to fast (not eat or drink anything except water) before getting an electrolyte blood test. But your healthcare provider may ask you to fast if the lab will be measuring other substances in your blood sample like cholesterol or blood sugar.

What should I expect during an electrolyte panel?

An electrolyte panel is a blood draw that takes a few minutes. Here’s what you can expect:

1. A phlebotomist checks your arms for an easily accessible vein. They may use an elastic band to start the flow of blood to a vein.
2. Once they locate a vein, they’ll clean and disinfect the area.
3. They insert a small needle into your vein. This may feel like a pinch.
4. They collect a small amount of blood in a test tube.
5. They remove the needle and hold a cotton ball or gauze on the site to stop the bleeding.
6. They put a bandage on the site.

What should I expect after an electrolyte panel?

There may be slight inflammation (swelling) or bruising at the needle site, which will go away in a few days.

You can take these steps to minimize bruising or discomfort:

• Place a wrapped ice pack on the bandaged area.
• Take an over-the-counter (OTC) pain reliever.
• Avoid lifting heavy items or exercising vigorously for 24 hours after the blood draw.

What are the risks of an electrolyte blood test?

A blood test carries little risk. You may experience a drop in blood pressure during a blood draw. Low blood pressure can make you dizzy or nauseous. Tell your provider if you feel unwell or like you might faint. Your provider can help you get more comfortable.

When will I get the test results from an electrolyte panel?

It may take several days for results to come back from a lab. Your healthcare provider will go over the results with you.

What are the normal ranges for electrolytes?

Your age, sex and preexisting health conditions can affect test results. And laboratories often use different methods for measuring electrolytes. This means results can vary from lab to lab.

Labs measure electrolytes by looking at the concentration of the substance in a specific amount of blood. In general, these are the normal ranges for electrolytes:

• Sodium: 135 to 145 mmol/L
• Potassium: 3.6 to 5.5 mmol/L
• Calcium: In adults, 8.8 to 10.7 mg/dL
• Chloride: 97 to 105 mmol/L
• Magnesium: 1.5 to 2.6 mg/dL
• Phosphate: 3.4 to 4.5 mg/dL
• Bicarbonate: 22 to 29 mmol/L

You should always discuss your specific results with your provider.

What happens if the electrolyte panel shows an electrolyte imbalance?

An electrolyte reading above or below the normal range doesn’t necessarily mean you have a problem that needs treatment. Depending on your symptoms or preexisting health condition, your provider may order additional tests.

These tests may include:

• Anion gap test, which uses results from the electrolyte panel to measure the difference (or gap) between electrolytes that have a positive charge and those that carry a negative charge. A gap that’s too high or low (negative) may indicate a problem with your lungs, kidneys or other organs.
• Blood gas test, which measures oxygen, carbon dioxide and acidity in your blood. It can help pinpoint the cause of an acid-base imbalance, like a lung or kidney problem.

What should I ask my healthcare provider?

You may want to ask your provider:

• Why do I need this test?
• Do I need to fast, stop smoking or not take medicines before I get the test?
• When will I get the test results?
• Should I be concerned about the test results?
• Will I need additional tests?
• How often do I need an electrolyte blood test?

What’s the difference between electrolyte panels and metabolic panels?

Differences between an electrolyte panel and a metabolic panel include:

• An electrolyte panel only checks electrolyte levels.
• A basic metabolic panel (BMP) measures the levels of certain electrolytes, along with creatinine, blood glucose and blood urea nitrogen (BUN).
• A comprehensive metabolic panel (CMP) is an expanded BMP test that also measures total protein in your blood, as well as liver enzymes.

Are there at-home electrolyte blood test kits?

No. Only trained medical professionals can do a blood draw for an electrolyte blood test.