Educational information only. At Precursor, blood testing is requested and reviewed by a clinician and considered alongside your history and other markers, not as a stand-alone diagnosis. Testing is performed in NATA-accredited laboratories to ISO 15189 standards.

What is potassium?

Potassium is the main electrolyte inside your cells and is essential for nerve signals and, critically, for the steady rhythm of your heart. The body keeps blood potassium within a narrow band, balancing intake against removal by the kidneys.

Why it matters

Potassium matters because both high and low levels can affect the heart, which is why it is one of the more clinically important electrolytes to keep in range. It is influenced by kidney function, hydration, medications and hormones, so it offers useful insight across several systems.

What your results can mean

If your result is higher

A high potassium can relate to kidney function or certain medications, and because it can affect heart rhythm it is always reviewed promptly by a clinician. Note that a sample can sometimes read falsely high due to how it was collected.

If your result is lower

A low potassium can follow fluid losses, certain medications or hormonal factors, and is likewise interpreted in clinical context.

Australian reporting and interpretation

Potassium is reported in millimoles per litre (mmol/L). The RCPA harmonised adult interval is 3.5 to 5.2 mmol/L, with a method note for laboratories using only heparin plasma. Use the interval printed on your own report and seek timely clinical advice for an unexpected result.

Test your electrolytes with Precursor

Potassium is read alongside your other electrolytes and kidney markers. At Precursor it is measured as part of Full Advanced Bloods, a single clinician-reviewed blood draw covering your kidney, heart, metabolic, hormonal, liver, thyroid and nutrient markers together, giving you and your clinician a broad baseline to understand and track.