Low potassium (hypokalemia) refers to a lower than normal potassium level in your bloodstream. Potassium helps carry electrical signals to cells in your body. It is critical to the proper functioning of nerve and muscles cells, particularly heart muscle cells.
Normally, your blood potassium level is 3.6 to 5.2 millimoles per liter (mmol/L). A very low potassium level (less than 2.5 mmol/L) can be life-threatening and requires urgent medical attention.
June 23, 2022
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- Adams JG. Potassium. In: Emergency Medicine: Clinical Essentials. 2nd ed. Philadelphia, Pa.: Saunders Elsevier; 2013. https://www.clinicalkey.com. Accessed May 5, 2017.
- Hypokalemia. The Merck Manuals: The Merck Manual for Health Care Professionals. http://www.merckmanuals.com/professional/endocrine_and_metabolic_disorders/electrolyte_disorders/hypokalemia.html. Accessed April 5, 2017.
- Mount DB, et al. Causes of hypokalemia in adults. http://www.uptodate.com/home. Accessed April 5, 2017.
- Mount DB, et al. Clinical manifestations and treatment of hypokalemia in adults. http://www.uptodate.com/home. Accessed April 5, 2017.
- Potassium, serum. Mayo Medical Laboratories. http://www.mayomedicallaboratories.com/test-catalog/Clinical+and+Interpretive/81390. Accessed April 28, 2017.