Arterial blood is drawn for potassium deficiency because it gives a better picture of potassium values and acid-base balance. Arterial blood is drawn for arterial blood gas analysis, a test that provides information on the levels of oxygen, carbon dioxide, acid-base balance, sodium ions and potassium ions in the patient’s blood. Potassium is an important element in maintaining normal physiological activity of the body. Both low and high potassium levels may have serious consequences such as muscle weakness, cardiac arrhythmia, secondary acid-base imbalance and even death. People with potassium deficiency are prone to hypokalemia and hyperkalemia due to oversupplementation of potassium. Therefore, doctors have to draw arterial blood for arterial blood gas analysis to monitor the patient’s blood potassium value and acid-base balance, and take timely and targeted therapeutic measures, such as the application of 5% sodium bicarbonate solution or dialysis treatment, etc., to prevent serious consequences. Patients with potassium deficiency should go to the hospital for examination and treatment as prescribed by the doctor to avoid the progression of the disease.