An electrolyte panel is a group of blood tests that measure electrolyte levels to assess the general functioning of the patient’s organ systems. Electrolytes are naturally occurring minerals in the body that carry an electrical charge. They help regulate a number of important bodily functions (e.g., fluid levels, heartbeat). Electrolytes that are commonly measured include calcium, potassium, chloride and sodium, although there are many others. The results of an electrolyte panel can help a physician make a diagnosis or monitor the progress of treatment with medications.


Abnormal electrolyte levels may be caused by several conditions, including many digestive system conditions. For example, the loss of fluids and salts caused by vomiting, diarrhea or gastrointestinal bleeding can reduce electrolyte levels. In other cases, an electrolyte condition can trigger problems in the digestive system. For instance, low levels of electrolytes can cause a person to become constipated.

Electrolyte tests are typically performed in a physician’s office or directly at the lab. Patients should follow physician’s restrictions on diet, exercise and medication use prior to having an electrolyte panel. Use of many types of medications – including antibiotics, antacids and laxatives – may affect results.

A blood sample is used to measure a patient’s electrolyte levels. The blood is usually drawn from a vein (venipuncture) from the inside of the elbow or the back of the hand. After the blood is collected, the needle is withdrawn and a small cotton ball or pad is applied with light pressure over the puncture site. Despite the precautions taken to avoid bruising and soreness, it does sometimes occur.

Once the sample has been obtained it is analyzed in a laboratory. An appropriate treatment will follow based on information revealed from the test if necessary. Electrolyte testing may also be used to monitor the progress of treatment. For this purpose, regular testing may be required.