What this marker measures
Potassium is particularly important for heart health — both high and low values can affect cardiac rhythm. Potassium is tightly regulated; small laboratory variations can sometimes reflect sample handling rather than true abnormalities.
High or low: what it can mean
High Potassium
Elevated potassium (hyperkalemia) can affect heart rhythm and muscle function. Common causes include kidney disease (reduced excretion), certain medications (ACE inhibitors, potassium-sparing diuretics), or a high-potassium diet in the context of reduced kidney function.
Read full explanation →
Low Potassium
Low potassium (hypokalemia) can cause muscle weakness, cramps, fatigue, and, if severe, heart rhythm disturbances. It is commonly caused by diuretics, diarrhea, vomiting, or low dietary intake.
Read full explanation →
Lifestyle considerations
- •Potassium-rich foods include bananas, potatoes, avocados, leafy greens, and beans
- •Diuretics and laxative overuse are common causes of low potassium — consult a doctor before stopping any prescribed medication
Frequently asked questions
What is Potassium?
+
Potassium is the main electrolyte inside cells and is critical for heart rhythm, muscle contraction, and nerve signal transmission.
What does Potassium measure?
+
Potassium is particularly important for heart health — both high and low values can affect cardiac rhythm. Potassium is tightly regulated; small laboratory variations can sometimes reflect sample handling rather than true abnormalities.
What does high Potassium mean?
+
Elevated potassium (hyperkalemia) can affect heart rhythm and muscle function. Common causes include kidney disease (reduced excretion), certain medications (ACE inhibitors, potassium-sparing diuretics), or a high-potassium diet in the context of reduced kidney function.
What does low Potassium mean?
+
Low potassium (hypokalemia) can cause muscle weakness, cramps, fatigue, and, if severe, heart rhythm disturbances. It is commonly caused by diuretics, diarrhea, vomiting, or low dietary intake.
What supports healthy Potassium levels?
+
Potassium-rich foods include bananas, potatoes, avocados, leafy greens, and beans. Diuretics and laxative overuse are common causes of low potassium — consult a doctor before stopping any prescribed medication
Related biomarkers
Editorial note
LabTestly explains lab markers using plain-English educational content. Reference ranges may vary by laboratory and should be interpreted with a clinician.
Educational content · Editorially reviewed for clarity · Last updated
Common sources used for lab-test education
Not medical advice
This page is for general understanding only and does not replace medical advice from your clinician. Reference ranges can vary by laboratory, age, sex, pregnancy status, medications, and clinical context.