What it is: A potassium blood test measures the level of potassium, an electrolyte essential for heart, nerve, and muscle function, in the blood.
Why it's ordered: Ordered as part of an electrolyte or metabolic panel to monitor kidney disease, heart conditions, or diuretic use, or when symptoms like muscle weakness or irregular heartbeat raise concern.
What it detects: Potassium is tightly regulated by the kidneys; both high and low levels can affect heart rhythm significantly, making this one of the more urgent electrolytes to correct when abnormal.
Collection & prep: A standard blood draw from a vein in the arm. Sample handling matters — hemolysis (cell rupture during or after the draw) can falsely raise results, so repeat testing is sometimes needed to confirm an abnormal value.
Results:
High (hyperkalemia) – can cause dangerous heart rhythm changes; linked to kidney disease, certain medications, or tissue injury
Low (hypokalemia) – can cause muscle weakness or heart rhythm changes; linked to vomiting, diarrhea, or diuretic use
Normal – heart and muscle function appear well-supported
Possible complications of a potassium imbalance: Significantly abnormal potassium levels can cause life-threatening heart arrhythmias, so markedly high or low results — especially with symptoms like palpitations or severe weakness — warrant prompt medical attention.
Statements made in the Clinical Manual have not been evaluated by the FDA. The products mentioned are not intended to diagnose, treat, cure or prevent any disease.
