Potassium (K) in Blood What Affects the Test
Reasons you may not be able to
have the test or why the results may not be helpful include:
Destruction of the red blood cells in the blood sample, which can happen when blood is taken or when it is being processed in the lab. When red blood cells are broken up, they release large amounts of potassium and can cause false high values. Taking potassium
supplements. Taking medicines, such as
antibiotics that contain potassium (such as a type of
nonsteroidal anti-inflammatory drugs (NSAIDs),
corticosteroids, diuretics, medicines used to treat
high blood pressure and heart disease, and natural licorice ( Glycyrrhiza glabra). The overuse of
laxatives. Severe vomiting. What To Think About Low blood potassium values are more common than
high blood potassium values. An
electrocardiogram (EKG or ECG) may show signs of a
very high or very low blood potassium level because of the effect potassium has
on the heart. To learn more, see the topic
Electrocardiogram. Other electrolyte tests, such as sodium, calcium, chloride,
magnesium, phosphate, blood urea nitrogen (BUN), and creatinine, are often done
at the same time as a test for potassium.
To learn more, see:
Sodium (Na) in Blood. Calcium (Ca) in Blood. Chloride (Cl). Magnesium (Mg). Phosphate. Blood Urea Nitrogen. Creatinine and Creatinine Clearance. Citations Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier. Other Works Consulted
Chernecky CC, Berger BJ (2008). Laboratory Tests and Diagnostic Procedures, 5th ed. St. Louis: Saunders.
Fischbach FT, Dunning MB III, eds. (2009). Manual of Laboratory and Diagnostic Tests, 8th ed. Philadelphia: Lippincott Williams and Wilkins.
Pagana KD, Pagana TJ (2010). Mosby’s Manual of Diagnostic and Laboratory Tests, 4th ed. St. Louis: Mosby Elsevier.
By Healthwise Staff Primary Medical Reviewer Adam Husney, MD - Family Medicine Specialist Medical Reviewer Avery L. Seifert, MD - Urology Last Revised September 4, 2012
WebMD Medical Reference from Healthwise
September 04, 2012
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