Potassium (Serum) Concentration
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
- 94007-2
- Short code
- Potassium 2h p Vaso SerPl-sCnc
- Synonyms
- Potassium 2h p Vaso 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 doctor may order this test to check for conditions affecting potassium levels, such as heart rhythm issues, kidney problems, or certain medications that alter potassium balance. It’s also used to monitor patients with conditions like heart failure, diarrhea, or vomiting.
What to Expect Before the Test
No special preparation is needed, but avoid eating or drinking for a few hours before the blood draw if instructed. Stay hydrated unless your doctor advises otherwise.
What Happens During the Test?
A healthcare provider will draw blood from a vein in your arm. You may feel a slight pinch, but it usually takes only a few minutes. The blood sample is then sent to a lab for analysis.
What the Results Mean
Results are compared to standard reference ranges to identify if your potassium levels are too high (hyperkalemia) or too low (hypokalemia). Abnormal levels may signal underlying health concerns.
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.
Changes in potassium levels can impact heart function, muscle weakness, or other organ systems. High levels may cause irregular heartbeats, while low levels can lead to fatigue, muscle cramps, or weakness. Your doctor will interpret results in the context of your overall health.
Short name
Serum Potassium
Frequently asked questions
What causes high potassium levels?
What causes low potassium levels?
How long does it take to get results?
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