Potassium
Also known as: K, K+, Serum potassium
Potassium is an electrolyte — a mineral that carries an electrical charge — that helps your nerves, muscles, and especially your heart work properly. Your body keeps it within a fairly narrow range.
Why it's measured
Potassium is part of routine metabolic panels. Because the body regulates it tightly, doctors pay attention when it falls outside the usual range. Sample handling can sometimes affect the reading.
Typical range
Many labs use a range of roughly 3.5 to 5.1 mmol/L, though this varies by lab. Occasionally the way a sample is collected or processed can influence the result, which your doctor will consider.
What high values can mean
A higher potassium is a value doctors look at carefully and sometimes confirm with a repeat test, because sample handling can occasionally raise it. It is interpreted alongside kidney function and medications.
What low values can mean
A lower potassium is another value doctors interpret in context, considering hydration, medications, and your overall picture.
Questions to ask your doctor
- Is my potassium something that needs rechecking?
- Could any medications I take affect this?
- How does this relate to my kidney results?
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Try the explainerEducational information only — not medical advice, diagnosis, or treatment. Reference ranges vary by lab; always use your own lab's range and discuss results with a qualified clinician.