Which of the following indicates a potassium level that is deficient?

A potassium level that is classified as deficient is typically indicated by a measurement that falls below 3.5 mEq/L. This threshold is significant because normal serum potassium levels range from approximately 3.5 to 5.0 mEq/L. When potassium levels drop below this normal range, it leads to a condition known as hypokalemia, which can result in various health issues, including muscle weakness, cramps, fatigue, and severe cardiac complications.

Understanding the implications of potassium levels is crucial in managing fluid and electrolyte balance in patients. Maintaining appropriate potassium levels is vital for heart function, nerve transmission, and muscle contraction, making it essential for overall health. Thus, identifying a deficiency at the level of below 3.5 mEq/L helps guide necessary interventions and treatments.