Potassium is one of several minerals found in the body known as electrolytes. Electrolytes keep fluid levels in the body balanced and are critical to maintaining the integrity of cells. The digestive system, heart, kidneys, muscles and nerves all need potassium to function properly.

Potassium offers many other benefits to the body, including building muscles and helping them contract, maintaining a stable acid-base balance in the body and protecting against high blood pressure, stroke, bone loss and kidney stones.

The best source of potassium is fresh foods of all types. Processed foods such as canned vegetables, many cereals and lunch meats contain less potassium and more sodium. Rich sources of potassium are found in certain fruits and vegetables.

Potassium deficiency (hypokalemia) and toxicity (hyperkalemia) are rare, but can cause various symptoms when they do occur. Hypokalemia is the most common source of electrolyte imbalance. Diuretics used to control high blood pressure are a major cause of potassium deficiency.

Hyperkalemia occurs when illnesses such as kidney problems cause excess potassium to build up. Both hypokalemia and hyperkalemia can be fatal when they are severe.