Hyperkalemia is a medical condition characterized by elevated levels of potassium in the blood. Potassium is an essential mineral that helps regulate heart function, muscle contractions, and nerve signals. Normal potassium levels range from 3.5 to 5.0 milliequivalents per liter (mEq/L). When levels exceed this range, it can lead to serious health issues. Common causes of hyperkalemia include kidney dysfunction, certain medications, and excessive potassium intake from food or supplements. Symptoms may include muscle weakness, fatigue, and irregular heartbeats. If left untreated, hyperkalemia can result in severe complications, including cardiac arrest.