Below the range
Common causes of a low Potassium (K⁺)
- Diuretics
- Vomiting or diarrhea (GI loss)
- Alkalosis
- Insulin or beta-agonist therapy
Looking for the other direction? See what causes a high Potassium (K⁺).
All tests · Electrolytes & Minerals · Potassium (K⁺)
Below the range
What causes a low Potassium (K⁺)?
Normal range 3.5-5 mEq/L (3.5-5 mmol/L SI). Specimen: Serum or plasma. See the full Potassium (K⁺) reference page for critical values and nursing considerations.
What is the normal range for Potassium (K⁺)?
The standard teaching reference range for Potassium (K⁺) is 3.5-5 mEq/L in conventional units, or 3.5-5 mmol/L in SI units. This value is measured in serum or plasma.
| Specimen | Serum or plasma |
|---|---|
| Conventional range | 3.5-5 mEq/L |
| SI range | 3.5-5 mmol/L |
| Critical value | < 2.5 or > 6.5 mmol/L (life-threatening arrhythmia risk) |
| Panel | Electrolytes & Minerals |
Full details, including nursing considerations, on the Potassium (K⁺) normal range page. Reference ranges vary by laboratory, method, age, sex, and population - always use the range printed on the actual result.
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