Electrolytes Test (Serum)

• The electrolyte test is mainly done in cases of suspected fluid loss or acid-base imbalances like severe dehydration, burns, cancer etc.
• It is also done in known cases of lung diseases, cardiac impairments and renal diseases where the electrolyte levels may be affected.
• Besides this, your doctor may prescribe an electrolytes serum test if you are prescribed medications such as ACE inhibitors or diuretics.

Electrolyte test is a blood test measuring the electrolyte levels. The sodium, potassium, and chloride levels are mainly measured under it.

An serum electrolyte test requires a simple blood draw. The phlebotomist will take a blood sample from a vein in your arm and send it to the lab for testing.

The electrolyte level may be low in cases of severe dehydration, burns, cancers, kidney diseases, cardiac abnormalities, acidosis [excess accumulation of acids in the body fluids] or alkalosis [too much alkaline in the blood]. Certain medications or severe vomiting may also affect the electrolyte levels in the blood. A few medical conditions may also lead to electrolyte overload leading to abnormally high electrolyte levels. 

Typically, fasting is not required for an serum electrolytes test. However, your healthcare provider may ask to fast if the doctor has prescribed additional blood tests such as blood sugar or cholesterol along with the electrolytes blood test.

There's no special preparation needed for an serum electrolytes test. However, confirm with your doctor if there are any specific instructions for your test. Let your doctor know about any medications, supplements, or vitamins you are taking, as these can affect the test results.

Just like any other blood test, the serum electrolytes test carries little risk. You may experience a slight drop in your blood pressure after the blood draw, which can make you feel nauseous or dizzy. Let your provider know if you are feeling unwell.

The normal range for electrolytes can vary slightly depending on the lab doing the test and the methodology used, but here's a general guideline for common electrolytes in adults:

• Potassium: 3.7 to 5.1 mmol/L
• Sodium: 136 to 144 mmol/L
• Chloride: 97 to 105 mmol/L
• Calcium: 8.5 to 10.2 mg/dL in adults
• Magnesium: 1.7 to 2.2 mg/dL
• Bicarbonate: 22 to 30 mmol/L
• Phosphate: 2.5 to 4.8 mg/dL

Your doctor may prescribe you certain additional tests depending on your health conditions and other symptoms you may be experiencing.

• Blood gas test: This test is used to measure the levels of acidity, carbon dioxide, and oxygen in our blood. Its results can help pinpoint the exact cause behind an acid-base imbalance in our body, such as a kidney or lung disorder.

• Serum Electrolyte Test
• Sodium
• Potassium
• Chlorides

Doctors may recommend an electrolytes serum test if one is exhibiting symptoms that depict a deficiency of electrolytes in our blood. The symptoms to watch out for include:

• Vomiting and nausea
• Weakness
• Confusion
• Irregular heartbeat