Potassium levels refer to the amount of potassium, an essential mineral, present in the blood. Potassium plays a crucial role in various bodily functions, including regulating heartbeats, muscle contractions, and nerve signals. Normal potassium levels typically range from 3.5 to 5.0 milliequivalents per liter (mEq/L). Abnormal potassium levels can lead to health issues. Low potassium, known as hypokalemia, can cause weakness, fatigue, and heart problems, while high potassium, or hyperkalemia, can lead to serious heart complications. Regular blood tests can help monitor potassium levels and ensure they remain within a healthy range.