Low potassium is a condition in which the potassium level in your bloodstream is lower than is typical. The medical term for this condition is hypokalemia. Potassium helps carry electrical signals to cells in your body. It is needed for healthy function of nerve and muscles cells, especially those in the heart.

Typically, your blood potassium level is 3.6 to 5.2 millimoles per liter (mmol/L). A blood potassium level of less than 3.0 mmol/L can be life-threatening. It requires urgent medical attention.