Potassium (K) | LabsVault

What is Potassium?

Potassium is the major intracellular cation (positively charged ion) essential for proper muscle and nerve function, including heart rhythm regulation. It plays a critical role in maintaining cellular fluid balance, blood pressure control, and proper muscle contractions. Even small changes in potassium levels can have significant clinical consequences.

Why is it Tested?

Doctors order potassium to monitor electrolyte balance, evaluate heart rhythm abnormalities, and assess kidney function. It’s crucial for patients taking medications that affect potassium levels, such as diuretics or ACE inhibitors. Regular monitoring helps prevent dangerous cardiac arrhythmias and muscle weakness.

Normal Ranges

Reference ranges vary by lab. General adult guidelines:

Adults: 3.5–5.0 mmol/L

Reference ranges vary by authority. Track yours across multiple standards with automatic unit conversions in LabsVault.

What do Abnormal Results Mean?

Abnormal results are not a diagnosis. Always discuss your results with a qualified healthcare provider before making any medical decisions.

Low Potassium

Low potassium (hypokalemia) may indicate:

Diuretic medications
Excessive vomiting or diarrhea
Primary hyperaldosteronism
Poor dietary intake or eating disorders

High Potassium

Elevated potassium (hyperkalemia) can result from:

Kidney disease or failure
ACE inhibitors or ARBs
Addison’s disease (adrenal insufficiency)
Hemolysis or tissue breakdown

How to Track Over Time

Potassium monitoring is critical for patients on medications affecting potassium levels or those with kidney disease. Even mild abnormalities can cause serious cardiac arrhythmias, making regular tracking essential for safety. Changes often reflect medication effects, dietary intake, or kidney function status.

Potassium