Potassium is a mineral in the body that helps maintain fluid
balance, nerve function, and muscle contraction, as well as the proper
transmission of electrical impulses in the heart. Potatoes and bananas are
especially good sources of potassium, which also is found in many meats, milks,
fruits, vegetables, and grains.
Both low and high potassium levels can disrupt the normal
electrical impulses in the heart, which leads to irregular heartbeats