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Electrolyte Panel

What is an electrolyte panel?

Electrolytes are minerals that have an electrical charge when they are dissolved in water or body fluids. You have electrolytes in your blood, urine, tissues, and other body fluids. They are important because they help:

  • Balance the amount of water in your body
  • Balance your body's acid-base (pH) level
  • Move nutrients into your cells
  • Move waste out of your cells
  • Support your muscle and nerve function
  • Keep your heart rate and rhythm steady
  • Keep your blood pressure stable
  • Keep your bones and teeth healthy

Electrolytes are in your blood, urine (pee), tissues, and other body fluids. An electrolyte panel is used to check for electrolyte, fluid, or pH imbalances.

An electrolyte panel, also known as a serum electrolyte test, is a blood test that measures levels of the body's main electrolytes:

  • Sodium, which helps control the amount of fluid in your body. It also helps your nerves and muscles work properly.
  • Chloride, which also helps control the amount of fluid in your body. In addition, it helps maintain healthy blood volume and blood pressure.
  • Potassium, which helps your cells, heart, and muscles work properly.
  • Bicarbonate, which helps maintain your body's acid- base balance (pH). It also plays an important role in moving carbon dioxide through the bloodstream.
  • Calcium, which helps make and keep your bones and teeth strong.
  • Magnesium, which helps your muscles, nerves, and heart work properly. It also helps control blood pressure and blood glucose (blood sugar) levels.
  • Phosphate, which works together with the mineral calcium to build strong bones and teeth.

You get these electrolytes from the foods you eat and the fluids you drink.

The levels of electrolytes in your body can become too low or too high. This can happen when the amount of water in your body changes. The amount of water that you take in should equal the amount you lose. If something upsets this balance, you may have too little water (dehydration) or too much water (overhydration).

Abnormal levels of any of these electrolytes can be a sign of a serious health problem, including kidney disease, high blood pressure, and a life-threatening type of arrhythmia (irregular heartbeat).

Other names: serum electrolyte test, electrolyte blood test, electrolyte lab test, lytes, sodium (Na), potassium (K), chloride (Cl), carbon dioxide (CO2)

What is it used for?

An electrolyte panel is often part of a routine blood screening or a comprehensive metabolic panel. The test may also be used to find out if your body has a fluid imbalance or an imbalance in acid and base levels.

Electrolytes are usually measured together. But sometimes they are tested individually. Separate testing may be done if your health care provider thinks that there might an imbalance of a specific electrolyte.

Why do I need an electrolyte panel?

You may need this test if you have symptoms indicating that your body's electrolytes may be out of balance. These include:

What happens during an electrolyte panel?

A health care professional will take a blood sample from a vein in your arm, using a small needle. After the needle is inserted, a small amount of blood will be collected into a test tube or vial. You may feel a little sting when the needle goes in or out. This usually takes less than five minutes.

Will I need to do anything to prepare for the test?

No special preparations are needed for an electrolyte panel.

Are there any risks to the test?

There is very little risk to having a blood test. You may have slight pain or bruising at the spot where the needle was put in, but most symptoms go away quickly.

What do the results mean?

Your results will include measurements for each electrolyte. Abnormal electrolyte levels can be caused by many different conditions, including:

  • Dehydration.
  • Kidney disease.
  • Heart disease.
  • Diabetes.
  • Lung infection (such as tuberculosis).
  • Malabsorption, a condition in which your body is not getting enough nutrients from the foods you eat.
  • Liver disease.
  • Acidosis, a condition in which you have too much acid in your blood. It can cause nausea, vomiting, and fatigue.
  • Alkalosis, a condition in which you have too much base in your blood. It can cause irritability, muscle twitching, and tingling in the fingers and toes.

An electrolyte imbalance can also happen if you take certain medicines, such as:

Your specific results will depend on which electrolyte or electrolytes are affected and whether levels are too low or too high. If your electrolyte levels were not in the normal range, it doesn't necessarily mean you have a medical problem needing treatment. Many factors can affect electrolyte levels. These include taking in too much fluid or losing fluid because of vomiting or diarrhea. Also, certain medicines such as antacids and blood pressure medicines may cause abnormal results.

An electrolyte imbalance means that the level of an electrolyte is too low or too high. The names of the imbalances are:

Electrolyte Too low Too high
Bicarbonate Acidosis Alkalosis
Calcium Hypocalcemia Hypercalcemia
Chloride Hypochloremia Hyperchloremia
Magnesium Hypomagnesemia Hypermagnesemia
Phosphate Hypophosphatemia Hyperphosphatemia
Potassium Hypokalemia Hyperkalemia
Sodium Hyponatremia Hypernatremia

If you have questions about your results, talk to your provider.

Learn more about laboratory tests, reference ranges, and understanding results.

Is there anything else I need to know about an electrolyte panel?

Your provider may order another test, called an anion gap blood test, along with your electrolyte panel. Some electrolytes have a positive electric charge. Others have a negative electric charge. The anion gap blood test is a measurement of the difference between the negatively charged and positively charged electrolytes. If the anion gap is either too high or too low, it may be a sign of a serious health problem.


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The information on this site should not be used as a substitute for professional medical care or advice. Contact a health care provider if you have questions about your health.