What is the normal reference range for serum potassium?

The normal serum potassium concentration typically ranges from 3.5 to 5.5 mmol/L; values above or below this range are considered abnormal.

Serum potassium refers to the concentration of potassium ions in the blood serum, with a normal reference range generally between 3.5 and 5.5 mmol/L. Potassium is a critical ion for maintaining cardiovascular function and neuromuscular excitability; only when serum potassium remains within the normal range can the body function properly. A level below 3.5 mmol/L indicates hypokalemia, whereas a level above 5.5 mmol/L indicates hyperkalemia. Therefore, both hyperkalemia and hypokalemia require prompt identification of the underlying cause followed by appropriate, targeted treatment.

Hypokalemia may lead to muscle weakness and generalized fatigue; severe cases can impair respiratory and cardiac muscle function, potentially resulting in respiratory arrest or cardiac arrest. Hyperkalemia also adversely affects cardiac function, causing arrhythmias and even cardiac arrest. Patients with hypokalemia are typically prescribed medications—including potassium chloride injection, potassium citrate granules, and potassium glutamate injection—under physician guidance to alleviate symptoms. Patients with hyperkalemia may be treated with diuretics such as bumetanide tablets or furosemide tablets, or with glucose and sodium chloride injection, as directed by their physician.

In daily life, it is advisable to cultivate healthy lifestyle habits: ensure adequate sleep, avoid staying up late, maintain a positive mood, and minimize stress, anxiety, and other negative emotions—all of which contribute to overall physical well-being.