Potassium concentration in serum
This test measures the amount of potassium, a mineral essential for heart function and nerve signaling, in your blood serum.
["Potassium levels help assess heart health and electrolyte balance."]
Key facts at a glance
- LOINC
- 12813-2
- Short code
- Potassium sp3 SerPl-sCnc
- Synonyms
- Potassium sp3 SerPl-sCnc
- Category
- electrolyte
- Sample
- serum
- Container
- Red-top tube (SST)
- 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
- 5 mL
- Stability
- Room temperature: 4h, Refrigerated: 24h, Frozen: 7d
- Hemolysis max
- 500
- Lipemia max
- 1000
- Icterus max
- 500
- TAT
- 4–24 hours
- Order
- routine
Why Is This Test Done?
Your healthcare provider may order this test to check for conditions affecting potassium levels, such as kidney problems, heart issues, or certain medications that alter electrolyte balance. It’s also used to monitor patients with conditions like heart failure, diarrhea, or vomiting, which can lead to potassium imbalances.
What to Expect Before the Test
No special preparation is usually needed, but you may be asked to fast for a few hours before the draw if your doctor specifies it. Wear a comfortable shirt for easy access to your arm.
How the Test Is Performed
A healthcare professional will insert a needle into a vein in your arm to draw a blood sample. You may feel a small pinch, but it usually takes only a few seconds. The blood is then sent to a lab for analysis.
What the Results Mean
Results are compared to standard reference ranges to identify any deviations. Low potassium (hypokalemia) or high potassium (hyperkalemia) can signal underlying health concerns that need attention.
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.
Potassium imbalances can cause serious issues like irregular heart rhythms, muscle weakness, or even life-threatening conditions. Regular monitoring is crucial for patients with chronic illnesses or those on medications that affect potassium levels.
Short name
Serum Potassium
Frequently asked questions
Why might my potassium levels be checked regularly?
What are common symptoms of low or high potassium?
Can diet affect potassium levels?
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