Potassium (Serum) Concentration
This test measures the amount of potassium, a vital mineral, in your blood serum. Potassium helps regulate heart rhythm, muscle function, and fluid balance.
["Potassium levels can affect heart health and muscle function."]
Key facts at a glance
- LOINC
- 39790-1
- Short code
- Potassium BldC-sCnc
- Synonyms
- Potassium BldC-sCnc
- Category
- electrolyte
- Sample
- whole-blood
- Container
- Lavender-top (EDTA)
- Units
- N/A
- Ref low
- 3.5
- Ref high
- 5
- Critical range
- 2.5 N/A – 6.5 N/A
- Fasting
- false
- Population
- adult
- Sex
- all
- Age range
- 18–65 years
- CPT
- 84132
- SNOMED
- 110742001
- Specimen volume
- 3 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h
- Hemolysis max
- 0
- Lipemia max
- 0
- Icterus max
- 0
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test to check for conditions like low potassium (hypokalemia), high potassium (hyperkalemia), kidney problems, or to monitor treatment for conditions such as heart disease, diabetes, or certain medications.
What to Expect Before the Test
No special preparation is needed. You may eat and drink normally before the test. The blood sample is usually taken from a vein in your arm.
What Happens During the Test?
A healthcare professional will clean the area with an antiseptic, insert a small needle into your vein, and collect a blood sample. The needle will be removed once the sample is taken, and pressure will be applied to stop any bleeding.
What Are Possible Results?
Results will be compared to standard reference ranges for potassium levels in serum. Abnormal results may indicate underlying health issues that need further evaluation.
Reference range
Adult: 3.5-5.0 mmol/LN/A
No special preparation required. Stay well hydrated.
Clinical interpretation
How abnormal results are interpreted and what conditions they suggest.
Low potassium levels (hypokalemia) can cause muscle weakness, cramps, irregular heartbeat, or even heart failure. High potassium levels (hyperkalemia) may lead to heart rhythm disturbances, muscle weakness, or numbness. Both conditions require prompt medical attention and may need treatment adjustments.
Short name
Serum Potassium
Frequently asked questions
What causes low potassium levels?
High potassium levels may be due to kidney disease, severe dehydration, certain medications (e.g., potassium-sparing diuretics), untreated Addison’s disease, or rapid cell breakdown (e.g., from severe burns or trauma).
Yes, diet plays a significant role. Foods rich in potassium include bananas, spinach, potatoes, avocados, and many fruits and vegetables. However, excessive intake can also lead to high potassium levels, especially in people with kidney issues.
Sources
- 1
- 2Lab Tests OnlineSource
- 3
Click any link to access the full source. PubMed Central (PMC) links provide free full-text access.
This information is for educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment.
This content is for general informational and educational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always seek the guidance of a qualified healthcare provider with any questions you have about a medical condition, and never disregard professional medical advice or delay seeking it because of something you read here.
If you think you may have a medical emergency, call your local emergency number or go to the nearest emergency department immediately.
Medically reviewed by WellAlly Editorial Team Last reviewed August 16, 2026. · Read our editorial policy