blood potassium test

blood potassium (K+) test

a blood test that detects the serum concentration of potassium, the major cation within cells. Potassium levels are followed carefully in patients with uremia, renal insufficiency, Addison's disease, or vomiting and diarrhea; in those on steroid therapy; in those taking potassium-depleting diuretics; and in those taking digitalis-like drugs.