Electrolyte testing, i.e. drawing blood from a vein to check the level of electrolytes in the blood, includes sodium, potassium, calcium, chloride, magnesium, etc., which can be used to observe the presence of electrolyte disorders. The human body contains a variety of electrolytes, including potassium, sodium, calcium, etc. The most common clinical electrolyte tests are the four electrolyte tests, i.e. sodium, potassium, calcium and chloride. Other electrolyte tests can also be performed according to the patient’s symptoms and signs. For example, patients with abnormal thyroid function need to check the magnesium level in the blood. Electrolyte four is the most common electrolyte test, according to the results of the test can be timely detection of high potassium, low potassium, high sodium, low sodium, etc. Abnormal electrolytes need to be dealt with in a timely manner, otherwise it may lead to poor prognosis, or even cause death. Electrolytes can reflect the patient’s internal environment, when the internal environment is disturbed, electrolyte disorders will occur, and timely intervention through drugs and other interventions are needed to maintain the homeostasis of the internal environment. Blood electrolyte test can reflect the physiological condition of the body, and when abnormalities occur, timely treatment or medication should be prescribed by the doctor.