Potassium, Serum
Serum potassium measures the amount of the electrolyte potassium in your blood. Potassium is essential for your heart rhythm, nerve signals, and muscle contraction.
Even small changes in potassium can affect how your heart and muscles work, so it's carefully monitored. Levels are influenced by your kidneys, hydration, diet, and many medications.
A higher potassium can relate to reduced kidney clearance, certain medications, or, sometimes, red blood cells breaking down in the sample during collection. Because it can affect heart rhythm, an unexpected high value is often rechecked by your clinician.
A lower potassium can come from fluid loss, some diuretics, or vomiting and diarrhea. Mild changes may cause no symptoms but are still worth discussing with your clinician.
A typical range is roughly 3.5 to 5.0 mmol/L. Your clinician can interpret your result.
Sources
Educational context only, not medical advice or a diagnosis. Reference ranges vary by lab, age and sex; always discuss your results with a clinician.